Abrasive article with shaped abrasive particles with predetermined rake angles

ABSTRACT

The present disclosure provides an abrasive article (10). The abrasive article (10) has a direction of use, a y-axis and a z-axis orthogonal to the y-axis and the direction of use. The abrasive article (10) further includes a backing (12) and shaped abrasive particles attached to the backing. About 5% to about 100% of the shaped abrasive particles (14) independently include a first side surface (16), a second side surface (18) opposed to the first side surface (16), a leading surface (20) connected to the first side surface (16) at a first edge (24) and connected to the second side surface (18) at a second edge (26), a rake angle (30) between the backing (12) and the leading surface (20) in a range of from about 10 degrees to about 110 degrees, and a z-direction rotational angle (50) between a line (52) intersecting the first edge (16) and second edge (18) and the direction of use (22) of the abrasive article (10) in a range of from about 10 degrees to about 170 degrees.

BACKGROUND

Abrasive particles and abrasive articles including the abrasive particles are useful for abrading, finishing, or grinding a wide variety of materials and surfaces in the manufacturing of goods. As such, there continues to be a need for improving the cost, performance, or life of abrasive particles or abrasive articles.

SUMMARY OF THE DISCLOSURE

The present disclosure provides an abrasive article. The abrasive article has a direction of use, a y-axis and a z-axis orthogonal to the y-axis and the direction of use. The abrasive article further includes a backing and shaped abrasive particles attached to the backing. About 5% to about 100% of the shaped abrasive particles independently include a first side surface, a second side surface opposed to the first side surface, a leading surface connected to the first side surface at a first edge and connected to the second side surface at a second edge, a rake angle between the backing and the leading surface in a range of from about 10 degrees to about 110 degrees, and a z-direction rotational angle between a line intersecting the first edge and second edge and the direction of use of the abrasive article in a range of from about 10 degrees to about 170 degrees.

The present disclosure further includes an abrasive article having a first direction of use. The abrasive article includes abrasive particles attached to a backing. Under the same testing conditions an amount of material removed from a workpiece in contact with the abrasive article is greater than an amount of material of the workpiece that is removed when the abrasive article is moved in a second direction different than the first direction of use.

The present disclosure further includes an abrasive article having a first direction of use. The abrasive article includes abrasive particles attached to a backing. Under the same testing conditions a surface roughness in a workpiece in contact with the abrasive article is greater than a surface roughness in the workpiece when the abrasive article is moved in a second direction of use different than the first direction of use.

The present disclosure further provides a method of making an abrasive article. The method includes orienting shaped abrasive particles and adhering the shaped abrasive particles to the backing. About 5% to about 100% of the abrasive particles are shaped and independently include a first side surface, a second side surface opposed to the first side surface, a leading surface connected to the first side surface at a first edge and connected to the second side surface at a second edge, a rake angle between the backing and the leading surface is in a range of from about 10 degrees to about 110 degrees, and a z-direction rotational angle between a line intersecting the first edge and second edge and a direction of use of the abrasive article in a range of from about 10 degrees to about 170 degrees.

The present disclosure further includes a method of using an abrasive article. The method includes contacting the shaped abrasive particles with a workpiece, moving the abrasive article relative to the workpiece in the direction of use; and removing a portion of the workpiece. About 5% to about 100% of the abrasive particles are shaped and independently include a first side surface, a second side surface opposed to the first side surface, a leading surface connected to the first side surface at a first edge and connected to the second side surface at a second edge, a rake angle between the backing and the leading surface in a range of from about 10 degrees to about 110 degrees, and a z-direction rotational angle between a line intersecting the first edge and second edge and a direction of use of the abrasive article in a range of from about 10 degrees to about 170 degrees.

BRIEF DESCRIPTION OF THE FIGURES

In the drawings, which are not necessarily drawn to scale, like numerals describe substantially similar components throughout the several views. Like numerals having different letter suffixes represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

FIG. 1A is a side view of an abrasive belt, in accordance with various embodiments.

FIG. 1B is a front view of the abrasive belt, in accordance with various embodiments.

FIG. 1C is a bottom view of the abrasive belt, in accordance with various embodiments.

FIG. 2 is a side view of an abrasive belt having a shaped abrasive particle, in accordance with various embodiments.

FIG. 3 is a bottom view of an abrasive disc, in accordance with various embodiments.

FIG. 4 is schematic diagram showing a method of making an abrasive article, in accordance with various embodiments.

FIG. 5 is a schematic diagram shown the orientation of a shaped abrasive particle according to the method of FIG. 4, in accordance with various embodiments.

FIG. 6 is a schematic diagram shown the orientation of a shaped abrasive particle according to the method of FIG. 4, in accordance with various embodiments.

FIG. 7 is a schematic diagram shown the orientation of a shaped abrasive particle according to the method of FIG. 4, in accordance with various embodiments.

FIG. 8 is a plot of the data from Grinding Procedure A, in accordance with various embodiments.

FIG. 9 is a plot of the data from Grinding Procedure B, in accordance with various embodiments.

FIG. 10 is a plot of the data from Grinding Procedure C, in accordance with various embodiments.

FIG. 11 is a 2D color contour height map of the substrate of Surface Analysis Procedure D abraded in the reverse direction, in accordance with various embodiments.

FIG. 12 is a 2D color contour height map of the substrate of Surface Analysis Procedure D abraded in the forward direction, in accordance with various embodiments.

FIG. 13 is a 3D image of the substrate of Surface Analysis Procedure D abraded in the reverse direction, in accordance with various embodiments.

FIG. 14 is a 3D image of the substrate of Surface Analysis Procedure D abraded in the forward direction, in accordance with various embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to certain embodiments of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section

In the methods described herein, the acts can be carried out in any order without departing from the principles of the disclosure, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%.

According to various embodiments of the present disclosure, an abrasive article is disclosed. The abrasive article can be chosen from many different abrasive articles such as an abrasive belt, an abrasive sheet or an abrasive disc. FIGS. 1A-1C are various views of abrasive belt 10. FIG. 1A is a side view of belt 10, FIG. 1B is a front view of belt 10, and FIG. 1C is a bottom view of belt 10. FIGS. 1A-1C show many of the same features and will be discussed concurrently. As shown in FIGS. 1A-1C, abrasive belt 10 has a z-axis and a y-axis orthogonal to the z-axis. Direction of use 22 for abrasive belt 10 extends in one direction along an x-axis orthogonal to both the z-axis and the y-axis. Relative to FIG. 1A, direction of use 22 is from left to right; relative to FIG. 1B, direction of use 22 is out of the page towards the reader; relative to FIG. 1C, direction of use 22 is from the bottom of the page to the top of the page.

Abrasive belt 10 includes backing 12 having shaped abrasive particles 14 attached thereto. Backing 12 can have any desirable degree of flexibility. Backing 12 can include any suitable material. For example, backing 12 can include a polymeric film, a metal foil, a woven fabric, a knitted fabric, paper, a vulcanized fiber, a nonwoven, a foam, a screen, a laminate, or combinations thereof. Backing 12 can further include various additive(s). Examples of suitable additives include colorants, processing aids, reinforcing fibers, heat stabilizers, UV stabilizers, and antioxidants. Examples of useful fillers include clays, calcium carbonate, glass beads, talc, clays, mica, wood flour; and carbon black.

As shown, an edge of least one shaped abrasive particle 14 is substantially in contact with backing 12. In additional embodiments, it may be possible for the edge or portions of the edge to be free of contact with backing 12.

Shaped abrasive particles 14 are any abrasive particle with at least a portion of the abrasive particle having a predetermined shape. The predetermined shape can be replicated, for example, from a mold cavity that is used to form a shaped precursor abrasive particle. In embodiments where the shaped abrasive particles 14 are formed in mold cavity, the predetermined geometric shape may substantially replicate the mold cavity used to form shaped abrasive particle 14. Shaped abrasive particles 14 may also replicate a shape of a die in examples where a shaped abrasive particle is formed through extrusion. Shaped abrasive particles 14 may also replicate a shape found in a program, for example, a computer-aided-design (CAD) program, if shaped abrasive particles 14 or the abrasive article is formed through an additive manufacturing process. Shaped abrasive particles 14 do not refer to randomly sized crushed abrasive particles formed, for example, by a mechanical crushing operation.

Shaped abrasive particles 14 include many geometric features. For example, as shown in FIGS. 1A-1C, shaped abrasive particles 14 include first side surface 16, second side surface 18, leading surface 20, and trailing surface 28. Surfaces of shaped abrasive particles 14 are joined at edges. For example, leading surface 20, is joined to first side surface 16 at edge 24 and further joined to second side surface 18 at edge 26. In operation, leading surface 20 is the leading surface of shaped abrasive particle 14 relative to direction of use 22 and trailing surface 28 is oppositely disposed with respect to leading surface 20. In some embodiments, any of leading surface 20, trailing surface 28, or both may be an edge formed at the intersection of two surfaces.

First side surface 16, second side surface 18, leading surface 20, and trailing surface 28 can have any suitable shape. For example, first side surface 16, second side surface 18, leading surface 20, and trailing surface 28 can have a polygonal shape that can be a regular polygon or an irregular polygon. In some embodiments, the polygonal shape can substantially conform to a triangular shape, quadrilateral shape, pentagonal shape, hexagonal shape, heptagonal shape, or octagonal shape. Other higher order polygonal shapes are within the scope of this disclosure. In embodiments, where the polygonal shape substantially conforms to a quadrilateral shape, the quadrilateral shape can be, for example, a square, rectangle, or trapezoid. In embodiments in which the polygonal shape substantially conforms to a triangular shape, the triangular shape can be, for example, a right triangle, a scalene triangle, an isosceles triangle, an acute triangle, or an obtuse triangle. In some embodiments, the triangular shape is not an equilateral triangle.

First side surface 16, second side surface 18, leading surface 20, and trailing surface 28 can have the same shape or have different shapes. Additionally, first side surface 16 and second side surface 18, can be substantially the same size or a substantially different size by at least one of surface area, a largest length dimension, a largest width dimension, or any combination thereof. Leading surface 20, and trailing surface 28 can each be smaller by at least one of surface area, a largest length dimension, a largest width dimension, or any combination thereof than each first side surface 16 and second side surface 18.

Any of first side surface 16, second side surface 18, leading surface 20, and trailing surface 28, can be substantially planar or non-planar. Additionally, any of first side surface 16, second side surface 18, leading surface 20, and trailing surface 28, can extend substantially parallel or non-parallel with respect to each other. In embodiments in which any of first side surface 16, second side surface 18, leading surface 20, and trailing surface 28 are non-planar, those surfaces can have a substantially concave or convex shape. In some embodiments, a portion of any one of first side surface 16, second side surface 18, leading surface 20, and trailing surface 28, can be substantially planar and another portion of the same surface can be non-planar. In additional embodiments, a portion of any one of first side surface 16, second side surface 18, leading surface 20, and trailing surface 28, can be substantially convex and another portion of the same surface can be substantially concave.

Depending on the shape or profile of any one of first side surface 16, second side surface 18, leading surface 20, and trailing surface 28; any edge such as edges 24 and 26 can be straight, tapered or curved. Edges connecting a particular surface to other surfaces can have the same length or a different length. For example, as shown in FIG. 1B, edges 24 and 26 are parallel and have the same length in the z-direction. This results in cutting tip 31 of shaped abrasive particle 14 extending in parallel with respect to the x-y plane. Cutting tip 31 is understood to refer to an inflection point along leading surface 20 and trailing surface 28. In other embodiments, edges 24 and 26 are different lengths and cutting tip 31 is angled such that is non-parallel with respect to the x-y plane. Cutting tip 31 can be free of a sharp point having a radius of curvature of at least about 60 microns, at least about 70 microns, at least about 80 microns, at least about 90 microns, or at least about 100 microns.

Any one of first side surface 16, second side surface 18, leading surface 20, and trailing surface 28, can include further shape features such as an opening, a concave surface, a convex surface, a groove, a ridge, a fractured surface, a low roundness factor, or a perimeter comprising one or more corner points having a sharp tip.

Shaped abrasive particle 14 can be positioned relative to backing 12 to achieve several performance characteristics of abrasive belt 10. The positioning of shaped abrasive particle 14 can be characterized by a variety of different angles of shaped abrasive particle 14, relative to backing 12.

For example, rake angle 30 can be characterized by an angle measured between backing 12 and leading surface 20 or cutting tip 31. As shown in FIG. 1A, rake angle 30 is about 90 degrees. However, in other embodiments, rake angle 30 can be chosen from a value in a range of from about 10 degrees to about 170 degrees, about 80 degrees to about 100 degrees, about 85 degrees to about 95 degrees, or less than, equal to, or greater than about 10 degrees, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, or about 170 degrees. The value of rake angle 30 can be selected for the intended purpose of abrasive belt 10. For example, if rake angle 30 is equal to or less than 90 degrees, the abrasive article may be well suited to remove material from a workpiece, achieve a deep cut in the workpiece, or remove a large piece of swarf from the workpiece. Conversely, if rake angle 30 is greater than 90 degrees, abrasive belt 10 may still have some of the characteristics previously described, but may additionally be better suited for finishing a surface of the workpiece.

In some embodiments of abrasive belt 10, it may be desirable for a certain percentage of shaped abrasive particles 14 to have substantially the same rake angle 30. For example, in some embodiments, rake angle 30 of about 50% to about 100% of the shaped abrasive particles is substantially the same, or about 90% to about 100%, or less than, equal to, or greater than about 50%, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100%. Having 100% of abrasive particles 14 or abrasive belt 10 sharing the same rake angle 30 can be desirable in achieving consistent performance in abrasive belt 10. However, in some embodiments of abrasive belt 10, it may be desirable to have different rake angles. For example, some embodiments of abrasive belt 10 may include a plurality of rows abrasive particles 14. With respect to FIG. 1A, three rows 40, 42, and 44 are shown, although other embodiments of abrasive belt 10 can include fewer or more rows. As shown, each of rows 40, 42, or 44 extends in the y-direction and adjacent rows (e.g., 40 and 42 as well as 42 and 44) are spaced relative to each other in the x-direction. In embodiments including multiple rows, it is possible for each abrasive particle 14 in a row to have the same rake angle 30. For example, each of shaped abrasive particles 14 of row 44 can have the same rake angle 30. Further, each of shaped abrasive particles 14 of row 42 can have the same rake angle 30, but this rake angle 30 can be different from that of shaped abrasive particles 14 of row 42. Further, each of shaped abrasive particles 14 of row 44 can have the same rake angle 30, but this rake angle 30 can be different from that of shaped abrasive particles 14 of row 42 and 40. In this manner a gradient of rake angles 30 can be created in abrasive belt 10.

A relief angle 46 is characterized by an angle measured between backing 12 and cutting tip 31 at the inflection point of trailing surface 28. As shown in FIG. 1A, relief angle 46 is measured between backing 12 and cutting tip 30 along trailing surface 28. In various embodiments, relief angle 46 can be in a range of from about 90 degrees to about 180 degrees, about 120 degrees to about 140 degrees, or less than, equal to, or greater than about 90 degrees, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, or about 180 degrees. In some embodiments the difference between rake angle 30 and relief angle 46 may be in a range of from about 5 degrees to about 50 degrees, about 10 degrees to about 40 degrees, or less than, equal to, or greater than about 5 degrees, 10, 15, 20, 25, 30, 35, 40, 45, or about 50 degrees. The value of relief angle 46 can be selected for the intended purpose of abrasive belt 10. For example, as relief angle 46 approaches higher values abrasive belt 10 may be able to finish a surface (e.g., if direction of use 22 is reversed to a second direction of use) Additionally, if relief angle 46 is a higher value, it may be possible for material removed from a workpiece to be ejected, thus helping to prevent clogging of abrasive belt 10. However, in some embodiments, having a lower value for relief angle 46 can help to strengthen the attachment of abrasive particle 14 to backing as force is applied to abrasive belt 10 during operation.

In some embodiments of abrasive belt 10, it may be desirable for a certain percentage of shaped abrasive particles 14 to have substantially the same relief angle 46. For example, in some embodiments, relief angle 46 of about 50% to about 100% of the shaped abrasive particles is substantially the same, or about 90% to about 100%, or less than, equal to, or greater than about 50%, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100%. Having 100% of abrasive particles 14 or abrasive belt 10 sharing the same relief angle 46 can be desirable in achieving consistent performance in abrasive belt 10. However, in some embodiments of abrasive belt 10, it may be desirable to have different relief angles 46. For example, each of shaped abrasive particles 14 of row 44 can have the same relief angle 46. Further, each of shaped abrasive particles 14 of row 42 can have the same relief angle 46, but this relief angle 46 is different from that of shaped abrasive particles 14 of row 42. Further, each of shaped abrasive particles 14 of row 44 can have the same relief angle 46, but this relief angle 46 is different from that of shaped abrasive particles 14 of row 42 and 40. In this manner a gradient of relief angles 46 can be created in abrasive belt 10.

A draft angle α 48 is characterized by an angle measured between backing 12 and any one of first side surface 16 and second side surface 18. As shown in FIG. 1B, draft angle α 48 is about 90 degrees. However, in other embodiments draft angle α 48 can be in a range of from about 90 degrees to about 130 degrees, about 95 degrees to about 120 degrees, or less than, equal to, or greater than about 90 degrees, 100, 105, 110, 115, 120, 125, or about 130 degrees. In some embodiments of abrasive belt 10, it may be desirable for a certain percentage of shaped abrasive particles 14 to have substantially the same draft angle α 48. For example, in some embodiments, draft angle α 48 of about 50% to about 100% of the shaped abrasive particles is substantially the same, or about 90% to about 100%, or less than, equal to, or greater than about 50%, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100%. Having 100% of abrasive particles 14 or abrasive belt 10 sharing the same draft angle α 48 can be desirable in achieving consistent performance in abrasive belt 10. However, in some embodiments of abrasive belt 10, it may be desirable to have different draft angles α 48. For example, each of shaped abrasive particles 14 of row 44 can have the same draft angle α 48. Further, each of shaped abrasive particles 14 of row 42 can have the same draft angle α 48, but this draft angle α 48 is different from that of shaped abrasive particles 14 of row 42. Further, each of shaped abrasive particles 14 of row 44 can have the same draft angle α 48, but this draft angle α 48 is different from that of shaped abrasive particles 14 of row 42 and 40. In this manner a gradient of draft angle α 48 can be created in abrasive belt 10. Alternatively, draft angle α 48 of adjacent shaped abrasive particles within the same row can be different to create a gradient in the y-direction.

A further angle to characterize shaped abrasive particles 14 can be z-direction rotational angle 50. As shown in FIG. 1C, z-direction rotational angle 50 can be defined between line 52, which intersects first edge 24 and second edge 26, and direction of use 22. Z-direction rotational angle 50 can be in a range of from about 10 degrees to about 170 degrees, about 80 degrees and about 100 degrees, about 85 degrees and about 95 degrees, or less than, equal to, or greater than about 10 degrees, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, or about 170 degrees.

In some embodiments of abrasive belt 10, it may be desirable for a certain percentage of shaped abrasive particles 14 to have substantially the same z-direction rotational angle 50. For example, in some embodiments, z-direction rotational angle 50 of about 50% to about 100% of the shaped abrasive particles is substantially the same, or about 90% to about 100%, or less than, equal to, or greater than about 50%, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100%. Having 100% of abrasive particles 14 or abrasive belt 10 sharing the same z-direction rotational angle 50 can be desirable in achieving consistent performance in abrasive belt 10. However, in some embodiments of abrasive belt 10, it may be desirable to have different z-direction rotational angles 50. For example, each of shaped abrasive particles 14 of row 44 can have the same z-direction rotational angle 50. Further, each of shaped abrasive particles 14 of row 42 can have the same z-direction rotational angle 50, but this z-direction rotational angle 50 is different from that of shaped abrasive particles 14 of row 42. Further, each of shaped abrasive particles 14 of row 44 can have the same z-direction rotational angle 50, but this z-direction rotational angle 50 different from that of shaped abrasive particles 14 of row 42 and 40. In this manner a gradient of z-direction rotational angles 50 can be created in abrasive belt 10. Alternatively, z-direction rotational angle 50 of adjacent shaped abrasive particles within the same row can be different to create a gradient in the y-direction.

FIGS. 1A-1C, show abrasive particles 14 as having a generally triangular shape conforming to that of a right triangle. However, in view of the foregoing, it is possible for any shaped abrasive particle 14 of abrasive belt 10 to have one of many other suitable shapes. As an example, FIG. 2 shows a side view of abrasive belt 10A including shaped abrasive particle 14A. As shown, shaped abrasive particle 14A has a generally triangular shape, however leading surface 20A has both convex portion 32 and concave portion 34. In embodiments, such as this where leading surface 20A is non-linear, rake angle 30 can be determined by measuring an angle between backing 12 and line 54. Line 54 is a line that is tangent to cutting tip 31.

FIGS. 1A-1C and FIG. 2 show embodiments in which the abrasive article is an abrasive belt or an abrasive sheet adapted for linear movement. In other embodiments, however, the abrasive article can be an abrasive disc that is adapted for rotational movement. FIG. 3 is a bottom view of abrasive disc 60. Abrasive disc 60 is adapted for rotational movement about central axis 62. The rotational direction of use 22A, can be determined with a line tangent to outer perimeter 64 of abrasive disc 60.

In abrasive disc 60, shaped abrasive particles 14 can possess the same properties as those of abrasive belt 10. For example, shaped abrasive particles can have the same rake angle 30, draft angle α 48, relief angle 46, and z-direction rotational angle 50 properties described herein with respect to FIGS. 1A-1C and FIG. 2. Each of rake angle 30, draft angle α 48, and relief angle 46 can be measured and determined in a manner consistent with those described above with respect to FIGS. 1A-1C and FIG. 2. In order to measure z-direction rotational angle 50 of each shaped abrasive particle 14 in abrasive disc 60, center of mass 66 of an individual shaped abrasive particle 14 is determined. Line 68 is drawn from central axis 62 through center of mass 66 to outer perimeter 64. A line tangent to outer perimeter 64, representing direction of use 22A, at the intersection between line 68 and outer perimeter 64 is imposed onto shaped abrasive particle 14 to pass through center of mass 66 and leading surface 20. Z-direction rotational angle 50 is then measured between the superimposed tangent line 22A and line 52.

Shaped abrasive particles 14 can account for 100 wt % of the abrasive particles in any abrasive article. Alternatively, shaped abrasive particles 14 can be part of a blend of abrasive particles distributed on backing 12. If present as part of a blend, shaped abrasive particles 14 may be in a range of from about 5 wt % to about 95 wt % of the blend, about 10 wt % to about 80 wt %, about 30 wt % to about 50 wt %, or less than, equal to, or greater than about, 5 wt %, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or about 95 wt %, of the blend. In the blend, the balance of the abrasive particles may include conventional crushed abrasive particles. Crushed abrasive particles are generally formed through a mechanical crushing operation and have no replicated shape. The balance of the abrasive particles can also include other shaped abrasive particles, that may for example, include an equilateral triangular shape (e.g., a flat triangular shaped abrasive particle or a tetrahedral shaped abrasive particle in which each face of the tetrahedron is an equilateral triangle).

Any abrasive article such as abrasive belt 10 or abrasive disc 60 can include a make coat to adhere shaped abrasive particles 14, or a blend of shaped abrasive particles 14 and crushed abrasive particles to backing 12. The abrasive article may further include a size coat adhering the shaped abrasive particles to the make coat. The make coat, size coat, or both can include any suitable resin such as a phenolic resin, an epoxy resin, a urea-formaldehyde resin, an acrylate resin, an aminoplast resin, a melamine resin, an acrylated epoxy resin, a urethane resin, or mixtures thereof. Additionally, the make coat, size coat, or both can include a filler, a grinding aid, a wetting agent, a surfactant, a dye, a pigment, a coupling agent, an adhesion promoter, or a mixture thereof. Examples of fillers may include calcium carbonate, silica, talc, clay, calcium metasilicate, dolomite, aluminum sulfate, or a mixture thereof.

Shaped abrasive particle 14 can be formed in many suitable manners for example, the shaped abrasive particle 14 can be made according to a multi-operation process. The process can be carried out using any material or precursor dispersion material. Briefly, for embodiments where shaped abrasive particles are monolithic ceramic particles, the process can include the operations of making either a seeded or non-seeded precursor dispersion that can be converted into a corresponding (e.g., a boehmite sol-gel that can be converted to alpha alumina); filling one or more mold cavities having the desired outer shape of shaped abrasive particle 14 with a precursor dispersion; drying the precursor dispersion to form precursor shaped abrasive particle; removing the precursor shaped abrasive particle 14 from the mold cavities; calcining the precursor shaped abrasive particle 14 to form calcined, precursor shaped abrasive particle 14; and then sintering the calcined, precursor shaped abrasive particle 14 to form shaped abrasive particle 14. The process will now be described in greater detail in the context of alpha-alumina-containing shaped abrasive particle 14. In other embodiments, the mold cavities may be filled with a melamine to form melamine shaped abrasive particles.

The process can include the operation of providing either a seeded or non-seeded dispersion of a precursor that can be converted into ceramic. In examples where the precursor is seeded, the precursor can be seeded with an oxide of an iron (e.g., FeO). The precursor dispersion can include a liquid that is a volatile component. In one example, the volatile component is water. The dispersion can include a sufficient amount of liquid for the viscosity of the dispersion to be sufficiently low to allow filling mold cavities and replicating the mold surfaces, but not so much liquid as to cause subsequent removal of the liquid from the mold cavity to be prohibitively expensive. In one example, the precursor dispersion includes from 2 percent to 90 percent by weight of the particles that can be converted into ceramic, such as particles of aluminum oxide monohydrate (boehmite), and at least 10 percent by weight, or from 50 percent to 70 percent, or 50 percent to 60 percent, by weight, of the volatile component such as water. Conversely, the precursor dispersion in some embodiments contains from 30 percent to 50 percent, or 40 percent to 50 percent solids by weight.

Examples of suitable precursor dispersions include zirconium oxide sols, vanadium oxide sols, cerium oxide sols, aluminum oxide sols, and combinations thereof. Suitable aluminum oxide dispersions include, for example, boehmite dispersions and other aluminum oxide hydrates dispersions. Boehmite can be prepared by known techniques or can be obtained commercially. Examples of commercially available boehmite include products having the trade designations “DISPERAL” and “DISPAL”, both available from Sasol North America, Inc., or “HIQ-40” available from BASF Corporation. These aluminum oxide monohydrates are relatively pure; that is, they include relatively little, if any, hydrate phases other than monohydrates, and have a high surface area.

The physical properties of the resulting shaped abrasive particle 14 can generally depend upon the type of material used in the precursor dispersion. As used herein, a “gel” is a three-dimensional network of solids dispersed in a liquid.

The precursor dispersion can contain a modifying additive or precursor of a modifying additive. The modifying additive can function to enhance some desirable property of the abrasive particles or increase the effectiveness of the subsequent sintering step. Modifying additives or precursors of modifying additives can be in the form of soluble salts, such as water-soluble salts. They can include a metal-containing compound and can be a precursor of an oxide of magnesium, zinc, iron, silicon, cobalt, nickel, zirconium, hafnium, chromium, yttrium, praseodymium, samarium, ytterbium, neodymium, lanthanum, gadolinium, cerium, dysprosium, erbium, titanium, and mixtures thereof. The particular concentrations of these additives that can be present in the precursor dispersion can be varied.

The introduction of a modifying additive or precursor of a modifying additive can cause the precursor dispersion to gel. The precursor dispersion can also be induced to gel by application of heat over a period of time to reduce the liquid content in the dispersion through evaporation. The precursor dispersion can also contain a nucleating agent. Nucleating agents suitable for this disclosure can include fine particles of alpha alumina, alpha ferric oxide or its precursor, titanium oxides and titanates, chrome oxides, or any other material that will nucleate the transformation. The amount of nucleating agent, if used, should be sufficient to effect the transformation of alpha alumina.

A peptizing agent can be added to the precursor dispersion to produce a more stable hydrosol or colloidal precursor dispersion. Suitable peptizing agents are monoprotic acids or acid compounds such as acetic acid, hydrochloric acid, formic acid, and nitric acid. Multiprotic acids can also be used, but they can rapidly gel the precursor dispersion, making it difficult to handle or to introduce additional components. Some commercial sources of boehmite contain an acid titer (such as absorbed formic or nitric acid) that will assist in forming a stable precursor dispersion.

The precursor dispersion can be formed by any suitable means; for example, in the case of a sol-gel alumina precursor, it can be formed by simply mixing aluminum oxide monohydrate with water containing a peptizing agent or by forming an aluminum oxide monohydrate slurry to which the peptizing agent is added.

Defoamers or other suitable chemicals can be added to reduce the tendency to form bubbles or entrain air while mixing. Additional chemicals such as wetting agents, alcohols, or coupling agents can be added if desired.

A further operation can include providing a mold having at least one mold cavity, or a plurality of cavities formed in at least one major surface of the mold. In some examples, the mold is formed as a production tool, which can be, for example, a belt, a sheet, a continuous web, a coating roll such as a rotogravure roll, a sleeve mounted on a coating roll, or a die. In one example, the production tool can include polymeric material. Examples of suitable polymeric materials include thermoplastics such as polyesters, polycarbonates, poly(ether sulfone), poly(methyl methacrylate), polyurethanes, polyvinylchloride, polyolefin, polystyrene, polypropylene, polyethylene or combinations thereof, or thermosetting materials. In one example, the entire tooling is made from a polymeric or thermoplastic material. In another example, the surfaces of the tooling in contact with the precursor dispersion while the precursor dispersion is drying, such as the surfaces of the plurality of cavities, include polymeric or thermoplastic materials, and other portions of the tooling can be made from other materials. A suitable polymeric coating can be applied to a metal tooling to change its surface tension properties, by way of example.

A polymeric or thermoplastic production tool can be replicated off a metal master tool. The master tool can have the inverse pattern of that desired for the production tool. The master tool can be made in the same manner as the production tool. In one example, the master tool is made out of metal (e.g., nickel) and is diamond-turned. In one example, the master tool is at least partially formed using stereolithography. The polymeric sheet material can be heated along with the master tool such that the polymeric material is embossed with the master tool pattern by pressing the two together. A polymeric or thermoplastic material can also be extruded or cast onto the master tool and then pressed. The thermoplastic material is cooled to solidify and produce the production tool. If a thermoplastic production tool is utilized, then care should be taken not to generate excessive heat that can distort the thermoplastic production tool, limiting its life.

Access to cavities can be from an opening in the top surface or bottom surface of the mold. In some examples, the cavities can extend for the entire thickness of the mold. Alternatively, the cavities can extend only for a portion of the thickness of the mold. In one example, the top surface is substantially parallel to the bottom surface of the mold with the cavities having a substantially uniform depth. At least one side of the mold, the side in which the cavities are formed, can remain exposed to the surrounding atmosphere during the step in which the volatile component is removed.

The cavities have a specified three-dimensional shape to make shaped abrasive particle 14. The depth dimension is equal to the perpendicular distance from the top surface to the lowermost point on the bottom surface. The depth of a given cavity can be uniform or can vary along its length and/or width. The cavities of a given mold can be of the same shape or of different shapes.

A further operation involves filling the cavities in the mold with the precursor dispersion (e.g., by a conventional technique). In some examples, a knife roll coater or vacuum slot die coater can be used. A mold release agent can be used to aid in removing the particles from the mold if desired. Examples of mold release agents include oils such as peanut oil or mineral oil, fish oil, silicones, polytetrafluoroethylene, zinc stearate, and graphite. In general, a mold release agent such as peanut oil, in a liquid, such as water or alcohol, is applied to the surfaces of the production tooling in contact with the precursor dispersion such that from about 0.1 mg/in² (0.6 mg/cm²) to about 3.0 mg/in² (20 mg/cm²), or from about 0.1 mg/in² (0.6 mg/cm²) to about 5.0 mg/in² (30 mg/cm²), of the mold release agent is present per unit area of the mold when a mold release is desired. In some embodiments, the top surface of the mold is coated with the precursor dispersion. The precursor dispersion can be pumped onto the top surface.

In a further operation, a scraper or leveler bar can be used to force the precursor dispersion fully into the cavity of the mold. The remaining portion of the precursor dispersion that does not enter the cavity can be removed from the top surface of the mold and recycled. In some examples, a small portion of the precursor dispersion can remain on the top surface, and in other examples the top surface is substantially free of the dispersion. The pressure applied by the scraper or leveler bar can be less than 100 psi (0.6 MPa), or less than 50 psi (0.3 MPa), or even less than 10 psi (60 kPa). In some examples, no exposed surface of the precursor dispersion extends substantially beyond the top surface.

In those examples where it is desired to have the exposed surfaces of the cavities result in planar faces of the shaped abrasive particles, it can be desirable to overfill the cavities (e.g., using a micronozzle array) and slowly dry the precursor dispersion.

A further operation involves removing the volatile component to dry the dispersion. The volatile component can be removed by fast evaporation rates. In some examples, removal of the volatile component by evaporation occurs at temperatures above the boiling point of the volatile component. An upper limit to the drying temperature often depends on the material the mold is made from. For polypropylene tooling, the temperature should be less than the melting point of the plastic. In one example, for a water dispersion of from about 40 to 50 percent solids and a polypropylene mold, the drying temperatures can be from about 90° C. to about 165° C., or from about 105° C. to about 150° C., or from about 105° C. to about 120° C. Higher temperatures can lead to improved production speeds but can also lead to degradation of the polypropylene tooling, limiting its useful life as a mold.

During drying, the precursor dispersion shrinks, often causing retraction from the cavity walls. For example, if the cavities have planar walls, then the resulting shaped abrasive particle 14 can tend to have at least three concave major sides. It is presently discovered that by making the cavity walls concave (whereby the cavity volume is increased) it is possible to obtain shaped abrasive particle 14 that have at least three substantially planar major sides. The degree of concavity generally depends on the solids content of the precursor dispersion.

A further operation involves removing resultant precursor shaped abrasive particle 14 from the mold cavities. The precursor shaped abrasive particle 14 can be removed from the cavities by using the following processes alone or in combination on the mold: gravity, vibration, ultrasonic vibration, vacuum, or pressurized air to remove the particles from the mold cavities.

The precursor shaped abrasive particle 14 can be further dried outside of the mold. If the precursor dispersion is dried to the desired level in the mold, this additional drying step is not necessary. However, in some instances it can be economical to employ this additional drying step to minimize the time that the precursor dispersion resides in the mold. The precursor shaped abrasive particle 14 will be dried from 10 to 480 minutes, or from 120 to 400 minutes, at a temperature from 50° C. to 160° C., or 120° C. to 150° C.

A further operation involves calcining the precursor shaped abrasive particle 14. During calcining, essentially all the volatile material is removed, and the various components that were present in the precursor dispersion are transformed into metal oxides. The precursor shaped abrasive particle 14 are generally heated to a temperature from 400° C. to 800° C., and maintained within this temperature range until the free water and over 90 percent by weight of any bound volatile material are removed. In an optional step, it can be desirable to introduce the modifying additive by an impregnation process. A water-soluble salt can be introduced by impregnation into the pores of the calcined, precursor shaped abrasive particle 14. Then the precursor shaped abrasive particle 14 are pre-fired again.

A further operation can involve sintering the calcined, precursor shaped abrasive particle 14 to form particles. In some examples where the precursor includes rare earth metals, however, sintering may not be necessary. Prior to sintering, the calcined, precursor shaped abrasive particle 14 are not completely densified and thus lack the desired hardness to be used as shaped abrasive particle 14. Sintering takes place by heating the calcined, precursor shaped abrasive particle 14 to a temperature of from 1000° C. to 1650° C. The length of time for which the calcined, precursor shaped abrasive particle 14 can be exposed to the sintering temperature to achieve this level of conversion depends upon various factors, but from five seconds to 48 hours is possible.

In another embodiment, the duration of the sintering step ranges from one minute to 90 minutes. After sintering, the shaped abrasive particle 14 can have a Vickers hardness of 10 GPa (gigaPascals), 16 GPa, 18 GPa, 20 GPa, or greater.

Additional operations can be used to modify the described process, such as, for example, rapidly heating the material from the calcining temperature to the sintering temperature, and centrifuging the precursor dispersion to remove sludge and/or waste. Moreover, the process can be modified by combining two or more of the process steps if desired.

Shaped abrasive particles 14 can be independently sized according to an abrasives industry recognized specified nominal grade. Abrasive industry recognized grading standards include those promulgated by ANSI (American National Standards Institute), FEPA (Federation of European Producers of Abrasives), and JIS (Japanese Industrial Standard). ANSI grade designations (i.e., specified nominal grades) include, for example: ANSI 4, ANSI 6, ANSI 8, ANSI 16, ANSI 24, ANSI 36, ANSI 46, ANSI 54, ANSI 60, ANSI 70, ANSI 80, ANSI 90, ANSI 100, ANSI 120, ANSI 150, ANSI 180, ANSI 220, ANSI 240, ANSI 280, ANSI 320, ANSI 360, ANSI 400, and ANSI 600. FEPA grade designations include F4, F5, F6, F7, F8, F10, F12, F14, F16, F18, F20, F22, F24, F30, F36, F40, F46, F54, F60, F70, F80, F90, F100, F120, F150, F180, F220, F230, F240, F280, F320, F360, F400, F500, F600, F800, F1000, F1200, F1500, and F2000. JIS grade designations include JIS8, JIS12, JIS16, JIS24, JIS36, JIS46, JIS54, JIS60, JIS80, JIS100, JIS150, JIS180, JIS220, JIS240, JIS280, JIS320, JIS360, JIS400, JIS600, JIS800, JIS1000, JIS1500, JIS2500, JIS4000, JIS6000, JIS8000, and JIS10,000.

In addition to the materials already described, at least one magnetic material may be included within or coated to an individual shaped abrasive particle 14. Examples of magnetic materials include iron; cobalt; nickel; various alloys of nickel and iron marketed as Permalloy in various grades; various alloys of iron, nickel and cobalt marketed as Fernico, Kovar, FerNiCo I, or FerNiCo II; various alloys of iron, aluminum, nickel, cobalt, and sometimes also copper and/or titanium marketed as Alnico in various grades; alloys of iron, silicon, and aluminum (about 85:9:6 by weight) marketed as Sendust alloy; Heusler alloys (e.g., Cu₂MnSn); manganese bismuthide (also known as Bismanol); rare earth magnetizable materials such as gadolinium, dysprosium, holmium, europium oxide, alloys of neodymium, iron and boron (e.g., Nd₂Fe₁₄B), and alloys of samarium and cobalt (e.g., SmCo₅); MnSb; MnOFe₂O₃; Y₃Fe₅O₁₂; CrO₂; MnAs; ferrites such as ferrite, magnetite; zinc ferrite; nickel ferrite; cobalt ferrite, magnesium ferrite, barium ferrite, and strontium ferrite; yttrium iron garnet; and combinations of the foregoing. In some embodiments, the magnetizable material is an alloy containing 8 to 12 weight percent (wt. %) aluminum, 15 to 26 wt. % nickel, 5 to 24 wt. % cobalt, up to 6 wt. % copper, up to 1% titanium, wherein the balance of material to add up to 100 wt. % is iron. In some other embodiments, a magnetizable coating can be deposited on an abrasive particle 14 using a vapor deposition technique such as, for example, physical vapor deposition (PVD) including magnetron sputtering.

Including these magnetizable materials can allow shaped abrasive particles 14 to be responsive a magnetic field. Any of shaped abrasive particles 14 can include the same material or include different materials. Additionally, if present shaped abrasive particles 14 and crushed abrasive particles may include the same or different materials.

The abrasive articles described herein can be manufactured according to many suitable methods. The methods described herein can allow for the precise placement of at least some of shaped abrasive particles 14 on backing 12. This can allow for precise and predetermined alignment of minor surface 20. This can also allow for a variety of predetermined patterns of shaped abrasive particles 14 to be formed. For example, in abrasive belt 10, z-direction rotational angle 50 of shaped abrasive particles 14 can be positioned such that a pattern formed by shaped abrasive particles 14 includes a plurality of parallel lines. As a further example, in abrasive disc 60, z-direction rotational angle 50 of shaped abrasive particles 14 can be positioned such that a pattern formed by shaped abrasive particles 14 includes a plurality of circles.

The abrasive articles described herein can be manufactured according to any suitable method. Generally stated, the abrasive articles can be formed by orienting at least a portion of shaped abrasive particles 14 on backing 12 to achieve at least one of rake angle 30, z-direction rotational angle 50, relief angle 46, draft angle α 48, or a combination thereof. The method can further include adhering shaped abrasive particles 14 to backing 12.

Orienting abrasive particles 14 can be accomplished, for example, by including one or more cavities in backing 12. The cavities can be shaped in such a manner that individual shaped abrasive particles 14 are positioned on backing 12 such that at least one of rake angle 30, z-direction rotational angle 50, relief angle 46, draft angle α 48, or a combination thereof achieve a predetermined value.

Including cavities in backing 12 can allow for abrasive particles 14 to be drop coated or electrostatically coated to backing 12 while achieving the intended orientation. As generally understood, in a drop coating technique, a bulk supply of abrasive particles 14 are fed through a hopper and fall onto backing 12 under the force of gravity and land in the cavities. Without the cavities, a spatial orientation of abrasive particles 14 upon contacting the backing 12 would be entirely random in all directions. However, the cavities take away the random spatial orientations.

In other embodiments, precise orientation of shaped abrasive particles 14 can be accomplished using a distribution tool or a screen. The distribution tool or screen can include one or more slots defined by a plurality of walls. The slots can be open on two ends. One end can be configured to receive shaped abrasive particle 14 and the other end can be in contact with backing 12. Backing 12 can optionally have a make coat distributed thereon. The slots are designed such that individual shaped abrasive particles 14 are positioned on backing 12 such that at least one of rake angle 30, z-direction rotational angle 50, relief angle 46, draft angle α 48, or a combination thereof achieve a predetermined value. Particles that do not properly enter the cavities can be swept from the distribution tool and additional particles can be contacted with the distribution tool to enter the vacant slots.

The distribution tool including shaped abrasive particles 14 can be left in contact with backing 12 for any suitable amount of time as the shaped abrasive particles 14 adhere to the make coat. After sufficient time has passed for good adhesion between shaped abrasive particles 14 and the make coat, the production tool is removed and a size coat is optionally disposed over shaped abrasive particles 14.

In other embodiments, precise orientation of shaped abrasive particles 14 can be achieved using a rotating production tool. The rotating production tool is circular and includes a plurality of cavities on an external surface. Each of the cavities are designed to receive shaped abrasive particles 14 in a particular orientation. In order to increase the probability that each cavity is filled, an excess of shaped abrasive particles 14 is contacted with production tool. Shaped abrasive particles 14 that do not enter the cavities are collected for later use. Once secured in the cavities, shaped abrasive particles 14 are contacted with backing 12, which can be supplied as a web. Backing 12 can have make coat pre-disposed thereon so that upon contact, shaped abrasive particles 14 adhere to backing 12 and are removed from the production tool.

In other embodiments, precise orientation of shaped abrasive particles 14 can be achieved using shaped abrasive particles that include at least some magnetic material. The shaped abrasive particles including at the magnetic material can be arranged randomly on backing 12. Shaped abrasive particles 14 can then be exposed to a magnetic field in such a manner that shaped abrasive particles 14 are rotated and aligned to achieve at least one of rake angle 30, z-direction rotational angle 50, relief angle 46, draft angle α 48. Once properly oriented, shaped abrasive particles 14 can be adhered to backing 12 with the make coat and optionally the size coat. As a result of this process, individual shaped abrasive particles 14 are positioned on backing 12 such that at least one of rake angle 30, z-direction rotational angle 50, relief angle 46, draft angle α 48, or a combination thereof achieve a predetermined value. An example of this process is described in further detail below with respect to FIGS. 4-7

FIG. 4 shows web 110 comprising backing 115 having make layer precursor 120 disposed thereon, which moves along web path 112 in a downweb direction 114 (e.g., machine direction). Web 110 has a crossweb direction (not shown) that is perpendicular to downweb direction 114. Make layer precursor 120 includes a first curable binder precursor (not shown). Magnetizable particles 132 (having a structure corresponding to shaped abrasive particles 14) are dropped through a portion of applied magnetic field 140 onto make layer precursor 120. At least some of magnetizable particles 132 are abrasive particles. Magnetizable particles 132 are predominantly deposited onto web 110 after travelling down downward sloping dispensing surface 185, which is fed from hopper 175. While travelling down downward sloping dispensing surface 185 the longest side of the magnetizable abrasive particles tends to align with applied magnetic field 140. Various web handling components 180 (e.g., rollers, conveyor belts, feed rolls, and take up rolls) handle web 110

Throughout the method, at least until transfer of the magnetizable abrasive particles to the make precursor layer, the magnetizable particles are continuously oriented by the applied magnetic field with their longest axis being aligned substantially parallel (or antiparallel) with the magnetic field lines 165. Once transferred, the applied magnetic field may continue to exert an orienting influence on the magnetizable abrasive particles, although this is not requirement.

In general, applied magnetic fields used in practice of the present disclosure have a field strength in the region of the magnetizable particles being affected (e.g., attracted and/or oriented) of at least about 10 gauss (1 mT), at least about 100 gauss (10 mT), or at least about 1000 gauss (0.1 T), although this is not a requirement

The applied magnetic field can be provided by one or more permanent magnets and/or electromagnet(s), or a combination of magnets and ferromagnetic members, for example. Suitable permanent magnets include rare-earth magnets comprising magnetizable materials are described hereinabove. The applied magnetic field can be static or variable (e.g., oscillating). The upper and/or lower magnetic members (152, 154), each having north (N) and south (S) poles, may be monolithic or they may be composed of multiple component magnets (154 a, 154 b) and/or magnetizable bodies, for example. If comprised of multiple magnets, the multiple magnets in a given magnetic member can be contiguous and/or co-aligned (e.g., at least substantially parallel) with respect to their magnetic field lines where the components magnets closest approach each other. Stainless steel retainers 156, 158 a, and 158 b retain the magnets in position. While stainless steel 304 or an equivalent is suitable due to its non-magnetic character, magnetizable materials may also be used. Mild steel mounts 162, 164 support the stainless steel retainers 156, 158 a and 158 b, respectively. While steel mounts are shown in FIG. 4 the mounts may be made of any dimensionally stable material(s) whether magnetizable or not.

The downward sloping dispensing surface may be inclined at any suitable angle, provided that the magnetizable particles can travel down the surface and be dispensed onto the web. Suitable angles may be in a range of from 15 to 60 degrees, although other angles may also be used. In some instances, it may be desirable to vibrate the downward sloping dispensing surface to facilitate particle movement, for example

The downward sloping dispensing surface may be constructed of any dimensionally stable material, that may be non-magnetizable. Examples include: metals such as aluminum; wood; and plastic.

FIGS. 5-7 depict the general process in FIG. 4 showing the alignment of the magnetizable particles 132 at the location of transfer from downward sloping dispensing surface 185 onto web 110 depending on the position of downward sloping dispensing surface 185 in the applied magnetic field 140.

For example, in the configuration shown in FIG. 5, magnetizable shaped abrasive particles 132 are dispensed onto web 110 where magnetic field lines 165 form downweb angle α with web 100 of less than 90 degrees such that when transferred to the web they attain an orientation with their long edges sloping upward from right to left. As shown, magnetizable shaped abrasive particles 132 slide down downward sloping dispensing surface 185 and begin to orient with their longest edge aligning with magnetic field lines 165. As magnetizable shaped abrasive particles 132 contact make layer precursor 120 of web 110, they are leaning downweb. Gravity and/or the lower magnetic member cause the magnetic shaped abrasive particles to sit down onto make layer precursor 120, and after curing they are subsequently adhered to backing 115. The majority of magnetizable shaped abrasive particles 132 are adhered with a nominal rake angle (e.g., the angle between the backing and the leading edge of a magnetizable shaped abrasive particle in an indicated direction (e.g., upweb or downweb) of about 90 degrees in the upweb direction

Referring now to the configuration shown in FIG. 6, magnetizable shaped abrasive particles 132 align such that when transferred to web 110 they attain an orientation with their longest edge sloping upward from either right to left or left to right. As magnetizable shaped abrasive particles 132 slide down downward sloping dispensing surface 185 and begin to orient with their longest edge aligning with magnetic field lines 165. Magnetizable shaped abrasive particles 132 are dispensed onto web 110 where magnetic field lines 165 are approximately perpendicular to web 110. Magnetizable shaped abrasive particles 132 are disposed onto web 110 with their longest edges approximately perpendicular to the backing. This allows the particles to rotate about their longest edge. The lower magnetic member and/or gravity causes magnetizable shaped abrasive particles 132 to sit down onto make layer precursor 120, and after curing they are subsequently adhered to backing 115. Roughly equal percentages of the magnetizable shaped abrasive particles have a nominal 90 degree rake angle facing the downweb direction as facing the upweb direction

In the configuration shown in FIG. 7, magnetizable shaped abrasive particles 132 align such that when transferred to the web they attain an orientation with their long edges sloping upward from left to right. As magnetizable shaped abrasive particles 132 slide down downward sloping dispensing surface 185, they begin to orient with their longest edge aligning with magnetic field lines 165. Magnetizable shaped abrasive particles 132 are dispensed on backing where magnetic field lines 165 downweb angle β with web 100 of greater than 90 degrees. As the particles contact the web, they are leaning forward in the downweb direction. The lower magnetic member and/or gravity causes magnetizable shaped abrasive particles 132 to sit down onto make layer precursor 120, and after curing they are subsequently adhered to backing 115. A majority of magnetizable shaped abrasive particles 132 become adhered to web 110 with a rake angle of about 90 degrees in the downweb direction.

Once the magnetizable particles are coated on to the curable binder precursor it is at least partially cured at a first curing station (not shown), so as to firmly retain the magnetizable particles in position. In some embodiments, additional magnetizable and/or non-magnetizable particles (e.g., filler abrasive particle and/or grinding aid particles) can be applied to the make layer precursor prior to curing.

In the case of a coated abrasive article, the curable binder precursor comprises a make layer precursor, and the magnetizable particles comprise magnetizable abrasive particles. A size layer precursor may be applied over the at least partially cured make layer precursor and the magnetizable abrasive particles, although this is not a requirement. If present, the size layer precursor is then at least partially cured at a second curing station, optionally with further curing of the at least partially cured make layer precursor. In some embodiments, a supersize layer is disposed on the at least partially cured size layer precursor.

According to various embodiments, a method of using an abrasive article such as abrasive belt 10 or abrasive disc 60 includes contacting shaped abrasive particles 14 with a workpiece or substrate. The workpiece or substrate can include many different materials such as steel, steel alloy, aluminum, plastic, wood, or a combination thereof. Upon contact, one of the abrasive article and the workpiece is moved relative to one another in direction of use 22 and a portion of the workpiece is removed.

According to various embodiments, a cutting depth into the substrate or workpiece can be at least about 10 μm, at least about 20 μm, at least about 30 μm, at least about 40 μm, at least about 50 μm, or at least about 60 μm. A portion of the substrate or workpiece is removed by the abrasive article as a swarf. A largest average dimension or length of the swarfs taken from a collection of swarf after on grinding cycle can be at least about 1200 μm millimeters, at least about 1250 μm, at least about 1300 μm, at least about 1350 μm, at least about 1400 μm, at least about 1450 μm, at least about 1500 μm, at least about 1500 μm, at least about 1550 μm, at least about 1600 μm, or at least about 1650 μm.

According to various embodiments, a cutting speed of the abrasive article can be at least about 100 m/min, at least about 110 m/min, at least about 120 m/min, at least about 130 m/min, at least about 140 m/min, at least about 150 m/min, at least about 160 m/min at least about 170 m/min, at least about 180 m/min, at least about 190 m/min, at least about 200 m/min, at least about 300 m/min, at least about 400 m/min, at least about 500 m/min, at least about 1000 m/min, at least about 1500 m/min, at least about 2000 m/min, at least about 2500 m/min, at least about 3000 m/min, or at least about 4000 m/min.

Direction of use 22 is a first direction indicated as indicated in FIGS. 1A-1C, 2 and 3. It is possible for the abrasive article to be moved in a second direction that is different than direction of use 22. The second direction can be in a direction rotated about 1 degree to 360 degrees relative to direction of use 22, about 160 degrees to about 200 degrees, less than, equal to, or greater than about 1 degree, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 230, 240, 250, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 350, 355, or about 360 degrees.

According to various embodiments, the abrasive articles described herein can have several advantages when moved in direction of use 22 as opposed to any other direction of use. For example, at the same applied force, cutting speed, or a combination thereof, an amount of material removed from the workpiece, length of a swarf removed from the workpiece, depth of cut in the workpiece, surface roughness of the workpiece or a combination thereof is greater in the first direction than in any other second direction.

For example, at least about 10% more material is removed from the substrate or workpiece in the first direction of use, or at least about 15%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 100%, at least about 120%, at least about 130%, at least about 140%, at least about 150%. In some embodiments, about 15% to about 500% more material is removed in the first direction of use, or about 30% to about 70%, or about 40% to about 60%, or less than, equal to, or greater than about 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, 200%, 205%, 210%, 215%, 220%, 225%, 230%, 235%, 240%, 245%, 250%, 255%, 260%, 265%, 270%, 275%, 280%, 285%, 290%, 295%, 300%, 305%, 310%, 315%, 320%, 325%, 330%, 335%, 340%, 345%, 350%, 355%, 360%, 365%, 370%, 375%, 380%, 385%, 390%, 395%, 400%, 405%, 410%, 415%, 420%, 425%, 430%, 435%, 440%, 445%, 450%, 455%, 460%, 465%, 470%, 475%, 480%, 485%, 490%, 495%, or about 500%. The amount of material removed can be in reference to an initial cut (e.g., the first cut of a cutting cycle) or a total cut (e.g., a sum of the amount of material removed over a set number of cutting cycles).

Procedures for grinding a workpiece are described herein in the Examples in Grinding Procedures A and B. An initial cut in a workpiece measured according to Grinding Procedure A (when the abrasive article is run in the direction of use) may be at least about 9 grams, at least about 9.5 grams, at least about 10 grams, at least about 10.5 grams, at least about 11 grams, at least about 11.5 grams, at least about 12 grams, at least about 12.5 grams, at least about 13 grams, at least about 13.5 grams, at least about 14 grams, at least about 14.5 grams, at least about 15 grams, at least about 15.5 grams, at least about 16 grams, at least about 16.5 grams, at least about 17 grams, at least about 17.5 grams, at least about 17.8 grams, at least about 18 grams, at least about 18.5 grams, at least about 19 grams, at least about 19.5 grams, at least about 20 grams, at least about 20.5 grams, at least about 21 grams, at least about 21.5 grams, at least about 22 grams, at least about 22.5 grams, at least about 23 grams, at least about 23.5 grams, at least about 24 grams, at least about 25.5 grams, or at least about 25 grams. A total cut in a workpiece measures according Grinding Procedure A (when the abrasive article is run in the direction of use) may be at least about 65 grams, at least about 70 grams, at least about 75 grams, at least about 80 grams, at least about 85 grams, at least about 90 grams, at least about 95 grams, at least about 100 grams, at least about 105 grams, at least about 110 grams, at least about 115 grams, at least about 118.37 grams, at least about 120 grams, or at least about 125 grams. An initial cut in a workpiece measured according to Grinding Procedure B (when the abrasive article is run in the direction of use) may at least about 9 mm, at least about 9.5 mm, at least about 10 mm, at least about 10.5 mm, at least about 11 mm, at least about 11.5 mm, at least about 12 mm, at least about 12.5 mm, at least about 13 mm, at least about 13.5 mm, at least about 14 mm, at least about 14.5 mm, at least about 15 mm, at least about 15.5 mm, at least about 16 mm, at least about 16.5 mm, at least about 17 mm, at least about 17.5 mm, at least about 18 mm, at least about 18.47 mm, at least about 19 mm, at least about 19.5 mm, at least about 20 mm, at least about 20.5 mm, at least about 21 mm, at least about 21.5 mm, at least about 22 mm, at least about 22.5 mm, at least about 23 mm, at least about 23.5 mm, at least about 24 mm, at least about 25.5 mm, or at least about 25 mm. A total cut in a workpiece measures according Grinding Procedure B (when the abrasive article is run in the direction of use) may be at least about 172 mm, at least about 180 mm, at least about 190 mm, at least about 200 mm, at least about 210 mm, at least about 220 mm, at least about 230 mm, at least about 240 mm, at least about 250 mm, at least about 260 mm, at least about 270 mm, at least about 280 mm, at least about 290 mm, at least about 300 mm, at least about 310 mm, at least about 320 mm, at least about 330 mm, at least about 340 mm, at least about 350 mm, at least about 360 mm, at least about 370 mm, at least about 380 mm, at least about 390 mm, at least about 400 mm, at least about 410 mm, at least about 420 mm, at least about 430 mm, at least about 440 mm, at least about 450 mm, at least about 460 mm, at least about 470 mm, at least about 480 mm, at least about 485.29 mm, at least about 490 mm, at least about 500 mm, at least about 510 mm, at least about 520 mm, at least about 530 mm, at least about 540 mm, at least about 550 mm, at least about 560 mm, at least about 570 mm, at least about 580 mm, at least about 590 mm, or at least about 600 mm.

As a further example, a depth of cut into the substrate or workpiece may be at least about 10% deeper in the first direction of use, or at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 100%, at least about 120%, at least about 130%, at least about 140%, at least about 150%. In some embodiments, about 10% to about 500% deeper in the first direction of use, or about 30% to about 70%, or about 40% to about 60%, or less than, equal to, or greater than about 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, 200%, 205%, 210%, 215%, 220%, 225%, 230%, 235%, 240%, 245%, 250%, 255%, 260%, 265%, 270%, 275%, 280%, 285%, 290%, 295%, 300%, 305%, 310%, 315%, 320%, 325%, 330%, 335%, 340%, 345%, 350%, 355%, 360%, 365%, 370%, 375%, 380%, 385%, 390%, 395%, 400%, 405%, 410%, 415%, 420%, 425%, 430%, 435%, 440%, 445%, 450%, 455%, 460%, 465%, 470%, 475%, 480%, 485%, 490%, 495%, or about 500%.

As a further example an arithmetical mean roughness value (Sa) of the workpiece or substrate cut by moving the abrasive article in first direction of use 22 can be higher than a corresponding substrate or workpiece cut under the exact same conditions but in the second direction of movement. For example the surface roughness can be about 30% greater when the workpiece or substrate is cut in the first direction or about 40% greater, about 50% greater, about 60% greater, about 70% greater, about 80% greater, about 90% greater, about 100% greater, about 110% greater, about 120% greater, about 130% greater, about 140% greater, about 150% greater, about 160% greater, about 170% greater, about 180% greater, about 190% greater, about 200% greater, about 210% greater, about 220% greater, about 230% greater, about 240% greater, about 250% greater, about 260% greater, about 270% greater, about 280% greater, about 290% greater, about 300% greater, about 310% greater, about 320% greater, about 330% greater, about 340% greater, about 350% greater, about 360% greater, about 370% greater, about 380% greater, about 390% greater, about 400% greater, about 410% greater, about 420% greater, about 430% greater, about 440% greater, about 450% greater, about 460% greater, about 470% greater, about 480% greater, about 490% greater, or about 500% greater. The arithmetical mean roughness value can be in a range of from about 1000 to about 2000, about 1000 to about 1100, or less than, equal to, or greater than about 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, or about 2000.

Although it may be desirable to move the abrasive article in first direction of use 22, there are some reasons to move the abrasive article in a second direction of movement other than first direction of use 22. For example, contacting the substrate or workpiece with the abrasive article and moving the abrasive article in the second direction may be beneficial for finishing the substrate or workpiece. While not intending to be bound to any particular theory, the inventors hypothesize that movement in the second direction may expose the substrate or workpiece to relief angle 46, which has a different value than rake angle 30 that is more suited for finishing applications.

EXAMPLES

ABBREVIATION DESCRIPTION AP1 Shaped abrasive particles were prepared according to the disclosure of U.S. Pat. No. 8,142,531. The shaped abrasive particles were prepared by molding alumina sol gel in a right triangle-shaped polypropylene mold cavities of leg side length 2.53 mm, hypotenuse length 3.58 mm and a mold depth of 0.71 mm. After drying and firing, the resulting shaped abrasive particles were about 2.0 mm (hypotenuse length) × 1.4 mm (leg side length) × 0.35 mm thick, with a draft angle approximately 98 degrees AP2 Shaped abrasive particles were prepared according to the disclosure of U.S. Pat. No. 8,142,531 (Adefris et al). The shaped abrasive particles were prepared by molding alumina sol gel in equilateral triangle- shaped polypropylene mold cavities. After drying and firing, the resulting shaped abrasive particles were about 1.4 mm (side length) × 0.35 mm (thickness), with a draft angle approximately 98 degrees. AP3 Aluminum oxide conforming the FEPA (Federation of the European Producers of Abrasives) standard for P60 (obtained under trade designation “DURALUM” in grit size 60 from Washington Mills, Grafton, Massachusetts.

Assembly of Magnet Apparatus (MAI)

Upper magnet assembly UM1 was formed from 3 identical rectangular magnets, each being 10.16 cm wide by 7.62 cm deep by 5.08 cm thick, magnetized through the thickness of grade N52 magnetic material (from SM Magnetics, Pelham, Ala.). These 3 magnets were arranged to form a magnet assembly 15.08 cm wide by 7.62 cm deep by 5.08 cm thick, with the magnetic pole of each magnet oriented in the same direction, with like poles in the same plane. This magnet arrangement was adhered to a plate of 1018 steel (110.16 cm wide by 12.7 cm deep by 7.62 cm thick) with epoxy resin (DP460, 3M Company, St. Paul, Minn.) and covered with a 0.476 cm thick sheet of 304 stainless steel.

First lower magnet assembly LM1 was formed in the identical manner as UM, with the exception being that the opposite poles were facing away from the steel plate.

Second lower magnet assembly LM2 was formed from 3 identical rectangular magnets, each being 10.16 cm wide by 15.24 cm deep by 5.08 cm thick, magnetized through the thickness of grade N52 magnetic material (from SM Magnetics, Pelham, Ala.). These 3 magnets were arranged to form a magnet assembly 15.08 cm wide by 15.24 cm deep by 5.08 cm thick, with the magnetic pole of each magnet oriented in the same direction as LM1, with like poles in the same plane. This magnet arrangement was adhered to a plate of 1018 steel (110.16 cm wide by 20.32 cm deep by 7.62 cm thick) with epoxy resin (DP460, 3M Company, St. Paul, Minn.) and covered with a 0.47625 cm thick sheet of 304 stainless steel.

A composite lower magnetic assembly LM3 was formed by combining LM1 and LM2. LM1 and LM2 and was arranged to form a magnet assembly 15.08 cm wide by 22.86 cm deep by 5.08 cm thick, with the 30.48 cm by 5.08 cm magnet faces in contact and the magnetic pole of each magnet oriented in the same direction, with like poles in the same plane. LM1 and LM2 were both bolted to a plate of 1018 steel (110.16 cm wide by 27.94 cm deep by 2.54 cm thick) to create LM3.

LM3 was positioned parallel to the upper magnet UM with a gap of 15.24 cm with both trailing edges aligned. UM1 and LM3 had opposite poles facing each other to create magnet apparatus MA1.

Preparation of Magnetizable Abrasive Particles (MAP1)

API was coated with 304 stainless steel using physical vapor deposition with magnetron sputtering. 304 Stainless steel sputter target, described by Barbee et al. in Thin Solid Films, 1979, vol. 63, pp. 143-150, deposited as the magnetic ferritic body centered cubic form. The apparatus used for the preparation of 304 stainless steel film coated abrasive particles (e.g., magnetizable abrasive particles) was disclosed in U.S. Pat. No. 8,698,394 (McCutcheon et al.). The physical vapor deposition was carried out for 4 hours at 1.0 kilowatt at an argon sputtering gas pressure of 10 millitorr (1.33 pascal) onto 51.94 grams of AP1. The weight percentage of metal coating in the coated AP1 was approximately 0.65% and the coating thickness is approximately 1 micron.

Preparation of Magnetizable Abrasive Particles (MAP2)

AP2 was coated with 304 stainless steel using physical vapor deposition with magnetron sputtering. 304 Stainless steel sputter target, described by Barbee et al. in Thin Solid Films, 1979, vol. 63, pp. 143-150, deposited as the magnetic ferritic body centered cubic form. The apparatus used for the preparation of 304 stainless steel film coated abrasive particles (i.e., magnetizable abrasive particles) was disclosed in U.S. Pat. No. 8,698,394 (McCutcheon et al.). The physical vapor deposition was carried out for 4 hours at 1.0 kilowatt at an argon sputtering gas pressure of 10 millitorr (1.33 pascal) onto 51.94 grams of AP2. The weight percentage of metal coating in the coated AP2 was approximately 0.65% and the coating thickness is approximately 1 micron.

Example 1

Untreated polyester cloth having a basis weight of 300-400 g/m², obtained under the trade designation “POWERSTRAIT” from Milliken & Company, Spartanburg, S.C., was pre-sized at the basis weight of 113 g/m² with a composition having 75 parts epoxy resin (bisphenol A diglycidyl ether, obtained under trade designation “EPON 828 from Resolution Performance Products, Houston, Tex.), 10 parts of trimethylolpropane triacrylate (obtained under trade designation “TMPTA from Cytec Industrial Inc., Woodland Park, N.J.), 8 parts of dicyandiamide curing agent (obtained under trade designation “DICYANEX 1400B” from Air Products and Chemicals, Allentown, Pa.), 5 parts of novolac resin (obtained under trade designation “RUTAPHEN 8656 from Momentive Specialty Chemicals Inc., Columbus, Ohio), 1 part of 2,2-dimethoxy-2-phenylacetophenone (obtained under trade designation “IRGACURE 651 photoinitiator from BASF Corporation, Florham Park, N.J.), and 0.75 part of 2-propylimidazole (obtained under trade designation “ACTIRON NXJ-60 LIQUID” from Synthron, Morganton, N.C.).

The cloth backing was coated with 209 g/m² of a phenolic make resin including of 52 parts of resole phenol-formaldehyde resin, 75 wt. % in water, (a 1.5:1 to 2.1:1 (Formaldehyde:Phenol) condensate catalyzed by 1 to 5% metal hydroxide and obtained from Georgia-Pacific, Atlanta, Ga.), 45 parts of calcium metasilicate (obtained under trade designation “M400 WOLLASTOCOAT” from NYCO Company, Willsboro, N.Y.), and 2.5 parts of water.

Abrasive particles MAP1 were dispensed to the make resin-coated backing via a sloped dispensing ramp as the backing was passing through magnet apparatus MA1 as shown in FIG. 4. The end of the sloped dispensing ramp was 1.27 cm from the surface of the backing and 15.87 cm from the bottom trailing corner of the upper magnet, as shown in FIG. 4. The coating weight of MAP1 was 480 grams/m². Immediately after abrasive particles MAP1 were coated onto the backing, abrasive particles AP3 were coated onto the backing with a coating weight of 376 grams/m².

The abrasive coated backing was placed in an oven at 90° C. for 1.5 hours to partially cure the make resin. A size resin consisting of 45.76 parts of resole phenol-formaldehyde resin, 75 wt. % in water, (a 1.5:1 to 2.1:1 (Formaldehyde:Phenol) condensate catalyzed by 1 to 5% metal hydroxide and obtained from Georgia-Pacific, Atlanta, Ga.), 4.24 parts of water, 24.13 parts of cryolite (Solvay Fluorides, LLC, Houston, Tex.), 24.13 parts calcium metasilicate (obtained under trade designation “M400 WOLLASTOCOAT” from NYCO Company, Willsboro, N.Y.) and 1.75 parts red iron oxide was applied to each strip of backing material at a basis weight of 712 g/m², and the coated strip was placed in an oven at 90° C. for 1 hour, followed by 8 hours at 102° C. After cure, the strip of coated abrasive was converted into a belt as is known in the art.

Comparative Example A

Untreated polyester cloth having a basis weight of 300-400 g/m², obtained under the trade designation “POWERSTRAIT” from Milliken & Company, Spartanburg, S.C., was pre-sized at the basis weight of 113 g/m² with a composition consisting of 75 parts epoxy resin (bisphenol A diglycidyl ether, obtained under trade designation “EPON 828 from Resolution Performance Products, Houston, Tex.), 10 parts of trimethylolpropane triacrylate (obtained under trade designation “TMPTA from Cytec Industrial Inc., Woodland Park, N.J.), 8 parts of dicyandiamide curing agent (obtained under trade designation “DICYANEX 1400B” from Air Products and Chemicals, Allentown, Pa.), 5 parts of novolac resin (obtained under trade designation “RUTAPHEN 8656 from Momentive Specialty Chemicals Inc., Columbus, Ohio), 1 part of 2,2-dimethoxy-2-phenylacetophenone (obtained under trade designation “IRGACURE 651 photoinitiator from BASF Corporation, Florham Park, N.J.), and 0.75 part of 2-propylimidazole (obtained under trade designation “ACTIRON NXJ-60 LIQUID” from Synthron, Morganton, N.C.).

The cloth backing was coated with 209 g/m² of a phenolic make resin consisting of 52 parts of resole phenol-formaldehyde resin, 75 wt. % in water, (a 1.5:1 to 2.1:1 (Formaldehyde:Phenol) condensate catalyzed by 1 to 5% metal hydroxide and obtained from Georgia-Pacific, Atlanta, Ga.) 45 parts of calcium metasilicate (obtained under trade designation “M400 WOLLASTOCOAT” from NYCO Company, Willsboro, N.Y.), and 2.5 parts of water.

Abrasive particles MAP2 were dispensed to the make resin-coated backing as the backing was passing through magnet apparatus MA1 as shown FIG. 4. The end of the sloped dispensing ramp was 1.27 cm from the surface of the backing and 15.87 cm from the bottom trailing corner of the upper magnet, as shown in FIG. 4. The coating weight of MAP1 was 480 grams/m². Immediately after abrasive particles MAP1 were coated onto the backing, abrasive particles AP3 were coated onto the backing with a coating weight of 376 grams/m².

The abrasive coated backing was placed in an oven at 90° C. for 1.5 hours to partially cure the make resin. A size resin having 45.76 parts of resole phenol-formaldehyde resin, 75 wt. % in water, (a 1.5:1 to 2.1:1 (Formaldehyde:Phenol) condensate catalyzed by 1 to 5% metal hydroxide and obtained from Georgia-Pacific, Atlanta, Ga.), 4.24 parts of water, 24.13 parts of cryolite (Solvay Fluorides, LLC, Houston, Tex.), 24.13 parts calcium metasilicate (obtained under trade designation “M400 WOLLASTOCOAT” from NYCO Company, Willsboro, N.Y.) and 1.75 parts red iron oxide was applied to each strip of backing material at a basis weight of 712 g/m², and the coated strip was placed in an oven at 90° C. for 1 hour, followed by 8 hours at 102° C. After cure, the strip of coated abrasive was converted into a belt as is known in the art.

Comparative Example B

Comparative example B is an abrasive grinding belt obtained under trade designation CUBITRON II CLOTH BELT 991FZ, grade 36+, 3M Company, St. Paul, Minn.

Comparative Example C

Comparative example B is an abrasive grinding belt obtained under trade designation CUBITRON II CLOTH BELT 984F, grade 36+, 3M Company, St. Paul, Minn.

Grinding Test Procedure A

Grinding Test Procedure A was used to evaluate the efficacy of the abrasive belt of Example 1, the abrasive belt of Comparative Example A, and the abrasive belt of Comparative Example C. The workpiece was an Aluminum 6061 bar that was presented to the abrasive belt along its 5.08 cm×91.44 cm. A 20.3 cm diameter, 70 durometer Shore A, serrated (1:1 land to groove ratio) rubber contact disc was used. The belt was run at 5500 surface feet per minute (SFM). The workpiece was urged against the center part of the belt at a blend of normal forces from 10 to 15 pounds (4.53 to 6.8 kg). The test included measuring the weight loss of the workpiece after 15 seconds of grinding (1 cycle). The workpiece was then cooled and tested again. The test was concluded after 15 test cycles. Cycle 1 is referred to as the initial cut of each Example. For Example 1 and Comparative Example C, the test was executed in a first direction of use in a forward direction and an opposite second direction of use in a reverse direction. The cut in grams was recorded after each cycle.

Results from Grinding Procedure A (aluminum) are presented herein at Table 1. A plot of the data is also provided at FIG. 8.

TABLE 1 Results from Grinding Test Procedure A. Comparative Comparative Example 1 Example 1 Example C Example C Cut in grams Cut in grams Comparative Cut in grams Cut in grams Cycle (run in forward (run in reverse Example A (run in reverse (run in forward Number direction) direction) Cut in grams direction) direction) 1 (initial cut) 17.8 10.91 8.95 10.9 8.9 2 11.37 8.5 6.25 6.96 5.39 3 9.43 7.29 5.29 5.51 4.75 4 9.04 6.4 4.95 5.02 4.36 5 9.05 6.17 4.77 4.71 4.21 6 8.24 6.11 4.77 4.5 3.86 7 7.74 5.71 4.69 4.47 3.98 8 7.11 5.28 4.49 4.25 3.81 9 6.26 5.02 4.44 4.1 3.96 10 5.89 4.89 4.43 3.95 3.71 11 5.91 4.65 4.35 4.15 3.72 12 5.64 4.71 4.28 4.07 3.62 13 5.48 4.64 4.12 3.91 3.56 14 4.86 4.5 3.89 3.86 3.51 15 4.55 4.58 4.08 3.86 3.41 Total Cut 118.37 89.36 73.75 74.22 64.75

Grinding Test Procedure B (Wood)

A 40.6 cm long x 30.48 cm×1.6 cm thick particle board workpiece obtained under the trade designation COLLINS PINE PARTICLE BOARD, Collins Co., of Portland Oreg., was secured to a test fixture in a position to be abraded on its 30.48 cm edge by the abrasive belts of Example A and Comparative Example B, each being endless abrasive belts having dimensions of 5.08 cm×91.44 cm. In each test, the abrasive belt was backed up by a graphite covered platen. In each test, the board was pressed into the abrasive belt as the belt is moving at a feed rate of 5500 surface feet per minute. A force of 15 pounds of total force was applied to the board and the board was left in contact with the abrasive belt for 10 seconds of grind time. The board was removed from the belt and the amount of material removed from the board was measured. The process was repeated for a total of 25 cycles. Cycle 1 is referred to as the initial cut of each Example. For Example 1 and Comparative Example B, the test was executed in a first direction of use in a forward direction and an opposite second direction of use in a reverse direction. The amount of material in mm of the particle board removed was recorded after each cycle. Results from Grinding Procedure B (particle board) are presented herein at Table 2. A plot of the data is also provided at FIG. 9.

TABLE 2 Results from Grinding Test Procedure B. Comparative Comparative Example 1 Example 1 Example B Example B amount of wood amount of wood amount of wood amount of wood removed in mm removed in mm removed in mm removed in mm Cycle (run in forward (run in forward (run in forward (run in reverse Number direction) direction) direction) direction) 1(initial cut) 18.47 8.7 7.61 8.54 2 20.35 7.78 7.46 7.85 3 20.51 7.71 7.54 7.84 4 20.43 7.17 7.5 7.72 5 20.24 7.36 7.56 7.71 6 20.51 7.33 7.1 7.65 7 20.32 7.01 7.56 7.66 8 20.55 6.92 7.2 7.51 9 20.45 7.21 7.35 7.52 10 20.23 7.06 7.17 7.56 11 19.93 7.26 7.19 7.31 12 19.79 6.99 7.49 7.36 13 18.47 6.95 7.01 7.47 14 18.24 6.94 6.99 7.26 15 18.06 7.07 6.86 7.62 16 18.13 6.96 6.8 7.39 17 17.93 6.98 6.59 7.47 18 18.43 6.98 6.31 7.42 19 18.81 7.42 6.45 7.42 20 19.24 6.8 6.37 7.18 21 19.15 6.96 6.17 7.04 22 18.98 7.04 6.5 7.03 23 19.04 7 5.73 6.99 24 19.17 7.11 5.5 6.89 25 19.86 7.17 5.33 6.75 Total Cut 485.29 179.88 171.34 186.16

Belt Force Data Procedure C

The abrasive belt of Example, the abrasive belt of Comparative Example A, and the abrasive belt of Comparative Example B. Test belts were endless belts each having dimensions of 5.08 cm×91.44 cm. Abrasive belts were mounted on a belt sander fitted with a 20.6 cm steel contact wheel. A 40.6 cm long x 30.48 cm×1.6 cm thick particle board workpiece COLLINS PINE PARTICLE BOARD, Collins Co., of Portland Oreg., was secured to a test fixture in a position to be abraded on its edge by the endless abrasive belt. The test fixture was adjusted to provide a 10 mm interference between the proximal surface of the edge of the workpiece and the surface of the abrasive belt. The belt sander was activated to a surface speed of 1753 m/min and the workpiece traversed along the 40.6 cm dimension at a rate of 150 mm/sec. For Example 1 and Comparative Example B, the test was executed in a first direction of use in a forward direction and an opposite second direction of use in a reverse direction. For Comparative Example B the test was executed in the second direction of use in the reverse direction. The cut in grams was recorded after each cycle.

The normal force at the abrasive belt/workpiece interface was measured as the specified volume of wood was abraded away. Following this first pass, the edge of the particle board was retracted from the abrasive belt, returned to its starting position, adjusted to provide another 10 mm interference, and traversed for another abrasion pass. This process was repeated for a total of 25 passes. Results from Grinding Procedure C are presented herein at Table 3. A plot of the data is also provided at FIG. 10.

TABLE 3 Results from Belt Force Data Procedure C Comparative Comparative Comparative Example 1 Example 1 Example A Example A Example B Infeed Force Infeed Force Infeed Force Infeed Force Infeed Force in pounds of in pounds of in pounds of in pounds of in pounds of total force total force total force total force total force Cycle (run in forward (run in reverse (run in forward (run in reverse (run in reverse number direction) direction) direction) direction) direction) 1 14.97 32.77 40.63 32.47 33.29 2 15.63 36.08 42.12 33.15 31.22 3 17.51 32.74 38.65 34.36 31.68 4 15.98 38.66 38.07 32.69 30.08 5 17.77 33.65 37.15 31.24 34.14 6 16.99 35.81 41.85 31.42 33.58 7 16.27 33.52 42.93 33.73 30.55 8 16.34 34.91 42.25 31.28 35.77 9 15.72 34.65 37.32 31.24 33.44 10 16.36 38.64 36.36 35.78 30.86 11 16.48 34.16 36.48 33.08 33.6 12 18.25 34.88 41.67 33.75 32.59 13 16.58 32.57 37.96 32 30.92 14 16.52 36 39.07 34.53 34.9 15 17.2 35.28 37.94 29.41 37.29 16 17.96 37.05 37.03 30.61 35.42 17 19.1 34.28 34.45 32.32 33.1 18 18.34 35.14 38.37 31.59 33.74 19 17.9 35.22 37.21 31.01 33.63 20 15.98 33.71 38.26 33.8 34.23 21 17.33 33.49 35.09 34.12 33.5 22 19.61 31.79 34.61 32.19 38.97 23 19.45 32.71 38.54 36.15 37.81 24 1.37 32.55 37.39 34.81 36.65 25 17.02 31.47 39.87 33.63 38.49

Workpiece Surface Analysis Procedure D

A portion of the workpiece of Example 1 run in the forward direction as well as the workpiece of Example 1 run in the reverse direction from grinding procedure A was analyzed using a microscope availed under the trade designation KEYENCE VK-X250 LASER CONFOCAL MICROSCOPE, available from Keyence Corporation of America (Itasca Ill.). A 10× objective lens was used. The 10× objective has a field of view of 1 mm×1.43 mm. To analyze a larger area, an image was created by stitching together a 3×3 array of individual images. This resulted in a field of view of 2.9 mm×3.9 mm for the final image.

The stitched images were then analyzed using the Keyence Multi-file Analyzer. A 2D color contour height map is shown in FIGS. 11 and 12. FIG. 11 shows the substrate of Example 1 run in the reverse direction and FIG. 12 shows the substrate of Example 1 run in the forward direction. A 3D image of each surface was also generated to show the differences between the samples. FIG. 13 shows a 3D image of the substrate of Example 1 run in the reverse direction and FIG. 14 shows the substrate of Example 1 run in the forward direction. Additionally, surface finish metrics for each surface were recorded and are presented in Table 4.

Parameters mentioned include the arithmetical mean height (Sa). Sa is the extension of Ra (arithmetical mean height of a line) to a surface. It is expressed, as an absolute value, the difference in height of each point is compared to the arithmetical mean of the surface. This parameter is used generally to evaluate surface roughness.

Skewness (Ssk) was also measured Ssk values represent the degree of bias of the roughness shape. An Ssk greater than 0 means that the height distribution is skewed above the mean plane (peaks); an Ssk equal to 0 means that height distribution (peaks and pits) is symmetrical around the mean plane; and an Ssk less than 0 means that a height distribution is skewed below the mean plane (pits).

Maximum peak height (Sp) was also measured. Sp is the height of the highest peak within the defined area. Maximum pit height (Sv) was also measured. Sv is the absolute value of the height of the largest pit within the defined area. Each of Sa, Ssk, Sp, and Sv were measured according to a standard known as ISO 25178.

TABLE 4 Surface Characteristics of Example 1. Ssk (“−” surface Sp Sv Sa skews pits, “+” (highest (lowest (μin) surface skews peaks) peak) pit) Example 1 belt 775.0 −0.2 3005.8 3552.7 run in reverse direction according to Grinding Test Procedure A Example 1 belt 1070.7 −0.6 3602.6 4625.1 run in forward direction according to Grinding Test Procedure A

Workpiece Swarf Analysis Procedure E

A portion of swarf was collected from the workpiece of Example 1 run in the forward direction. A portion of swarf was also collected from the workpiece of Comparative Example C run in the forward direction.

Scanning electron microscopy (SEM) was used to analyze the respective swarf portions. A Field Emission Scanning Electron Microscope available under the trade designation JSM-7600F Field Emission Scanning Electron Microscope, available from JEOL Ltd (Tokyo Japan) was used to capture images of the swarf. Images using the Jeol JSM-7600F were taken at 33× with 45 degrees of tilt and were stitched into a 2×2 composite.

A microscope available under the trade designation KEYENCE 5000 DIGITAL MICROSCOPE, available from Keyence Corporation of America (Itasca Ill.) was used to measure the mean length of the swarf collected from Example 1 and Comparative Example C. The mean length was measured using binary image analytics to calculate a maximum diagonal length.

Analysis showed that the mean length for 78 pieces of the swarf collected from Example 1 was 1772 μm. Additional analysis showed that the mean length for 89 pieces of the swarf collected from Comparative Example C was 1109 μm.

Additional Embodiments

The following exemplary embodiments are provided, the numbering of which is not to be construed as designating levels of importance:

Embodiment 1 provides an abrasive article having a direction of use, a y-axis and a z-axis orthogonal to the y-axis and the direction of use, the abrasive article comprising:

a backing;

shaped abrasive particles attached to the backing, about 5% to about 100% of the shaped abrasive particles independently comprising:

-   -   a first side surface,     -   a second side surface opposed to the first side surface,     -   a leading surface connected to the first side surface at a first         edge and connected to the second side surface at a second edge,     -   a rake angle between the backing and the leading surface in a         range of from about 10 degrees to about 110 degrees, and     -   a z-direction rotational angle between a line intersecting the         first edge and second edge and the direction of use of the         abrasive article in a range of from about 10 degrees to about         170 degrees.

Embodiment 2 provides an abrasive article having a first direction of use, the abrasive article comprising:

abrasive particles attached to a backing, wherein under the same testing conditions an amount of material removed from a workpiece in contact with the abrasive article is greater than an amount of material of the workpiece that is removed when the abrasive article is moved in a second direction different than the first direction of use.

Embodiment 3 provides the abrasive article of Embodiment 2, wherein at least 15% more material is removed in the first direction of use.

Embodiment 4 provides the abrasive article of any one of Embodiments 2 or 3, wherein at least 50% more material is removed in the first direction of use.

Embodiment 5 provides the abrasive article of Embodiment 2, wherein about 10% to about 500% more material is removed in the first direction of use.

Embodiment 6 provides the abrasive article of any one of Embodiments 1 or 5, wherein about 30% to about 70% more material is removed in the first direction of use.

Embodiment 7 provides the abrasive article of any one of Embodiments 1 or 5-6 wherein about 40% to about 60% more material is removed in the first direction of use.

Embodiment 8 provides the abrasive article of any one of Embodiments 2-7, wherein about 5% to about 100% of the abrasive particles are shaped abrasive particles independently comprising:

a first side surface,

a second side surface opposed to the first side surface,

a leading surface connected to the first side surface at a first edge and connected to the second side surface at a second edge,

a rake angle between the backing and the leading surface in a range of from about 10 degrees to about 110 degrees, and

a z-direction rotational angle between a line intersecting the first edge and second edge and the direction of use of the abrasive article in a range of from about 10 degrees to about 170 degrees.

Embodiment 9 provides the abrasive article of any one of Embodiments 2-8, wherein the material is removed according to at least one of Grinding Procedure A and Grinding Procedure B.

Embodiment 10 provides the abrasive article of Embodiment 9, wherein an initial cut of the workpiece when the abrasive article is run in the direction of use according Grinding Procedure A is at least 9 grams.

Embodiment 11 provides the abrasive article of any one of Embodiments 9 or 10, wherein an initial cut of the workpiece when the abrasive article is run in the direction of use according Grinding Procedure A is at least 11 grams.

Embodiment 12 provides the abrasive article of any one of Embodiments 9-11, wherein an initial cut of the workpiece when the abrasive article is run in the direction of use according Grinding Procedure A is at least 17.8 grams.

Embodiment 13 provides the abrasive article of any one of Embodiments 9-12, wherein a total cut of the workpiece when the abrasive article is run in the direction of use according to Grinding Procedure A after 15 cycles is at least 65 grams.

Embodiment 14 provides the abrasive article of any one of Embodiments 9-13, wherein a total cut of the workpiece when the abrasive article is run in the direction of use according to Grinding Procedure A after 15 cycles is at least 118.37 grams.

Embodiment 15 provides the abrasive article of any one of Embodiments 9-14, wherein a total cut of the workpiece when the abrasive article is run in the direction of use according to Grinding Procedure A after 15 cycles is at least 120 grams.

Embodiment 16 provides the abrasive article of Embodiment 9, wherein an initial cut of the workpiece when the abrasive article is run in the direction of use according Grinding Procedure B is at least 9 mm.

Embodiment 17 provides the abrasive article of any one of Embodiments 9 or 16, wherein an initial cut of the workpiece when the abrasive article is run in the direction of use according Grinding Procedure B is at least 11 mm.

Embodiment 18 provides the abrasive article of any one of Embodiments 9, 16 or 17, wherein an initial cut of the workpiece when the abrasive article is run in the direction of use according Grinding Procedure B is at least 18.47 mm.

Embodiment 19 provides the abrasive article of any one of Embodiments 9 or 16-19, wherein a total cut of the workpiece when the abrasive article is run in the direction of use according to Grinding Procedure B after 25 cycles is at least 180 mm.

Embodiment 20 provides the abrasive article of any one of Embodiments 9 or 16-19, wherein a total cut of the workpiece when the abrasive article is run in the direction of use according to Grinding Procedure B after 25 cycles is at least 187 mm.

Embodiment 21 provides the abrasive article of any one of Embodiments 9 or 16-20, wherein a total cut of the workpiece when the abrasive article is run in the direction of use according to Grinding Procedure B after 25 cycles is at least 485.29 mm.

Embodiment 22 provides an abrasive article having a first direction of use, the abrasive article comprising:

abrasive particles attached to a backing, wherein under the same testing conditions an average surface roughness of a workpiece abraded with the abrasive article is greater than an average surface roughness of a workpiece abraded when the abrasive article is moved in a second direction of use different than the first direction of use.

Embodiment 23 provides the abrasive article of Embodiment 22, wherein the average surface roughness is at least 90% greater in the first direction of use.

Embodiment 24 provides the abrasive article of any one of Embodiments 22 or 23, wherein the average surface roughness is at least 105% greater in the first direction of use.

Embodiment 25 provides the abrasive article of Embodiment 22, wherein the average surface roughness is about 10% to about 500% greater in the first direction of use.

Embodiment 26 provides the abrasive article of any one of Embodiments 22-25, wherein about 5% to about 100% of the abrasive particles are shaped abrasive particles independently comprising:

a first side surface,

a second side surface opposed to the first side surface,

a leading surface connected to the first side surface at a first edge and connected to the second side surface at a second edge,

a rake angle between the backing and the leading surface in a range of from about 10 degrees to about 110 degrees, and

a z-direction rotational angle between a line intersecting the first edge and second edge and the direction of use of the abrasive article in a range of from about 10 degrees to about 170 degrees.

Embodiment 27 provides the abrasive article of any one of Embodiments 9-26, wherein the workpiece is abraded according to at least one of Grinding Procedure A and Grinding Procedure B.

Embodiment 28 provides the abrasive article of any one of Embodiments 1-27, wherein about 25% to about 100% comprise the first side surface, second side surface, leading surface, rake angle, and z-direction rotational angle.

Embodiment 29 provides the abrasive article of any one of Embodiments 1-28, wherein about 50% to about 100% comprise the first side surface, second side surface, leading surface, rake angle, and z-direction rotational angle.

Embodiment 30 provides the abrasive article of any one of Embodiments 1-29, wherein the backing is a flexible backing comprising a polymeric film, a metal foil, a woven fabric, a knitted fabric, paper, a vulcanized fiber, a nonwoven, a foam, a screen, a laminate, or combinations thereof.

Embodiment 31 provides the abrasive article of any one of Embodiments 1-30, wherein at least one of the shaped abrasive particles is a ceramic shaped abrasive particle.

Embodiment 32 provides the abrasive article of any one of Embodiments 1-31, wherein the shaped abrasive particles independently comprise alpha alumina, sol-gel derived alpha alumina, or a mixture thereof.

Embodiment 33 provides the abrasive article of any one of Embodiments 1-32 wherein the shaped abrasive particles independently comprise a fused aluminum oxide, a heat-treated aluminum oxide, a ceramic aluminum oxide, a sintered aluminum oxide, a silicon carbide material, titanium diboride, boron carbide, tungsten carbide, titanium carbide, diamond, cubic boron nitride, garnet, fused alumina-zirconia, cerium oxide, zirconium oxide, titanium oxide or a combination thereof.

Embodiment 34 provides the abrasive article of any one of Embodiments 1-33, wherein the first side surface and the second side surface of at least one of the shaped abrasive particles comprise a polygonal shape.

Embodiment 35 provides the abrasive article of Embodiment 34, wherein the polygonal shape of the first side surface and the second side surface are independently a regular polygon or an irregular polygon.

Embodiment 36 provides the abrasive article of any one of Embodiments 33 or 34, wherein the polygonal shape of the first side surface and the second side surface are independently a triangular shape or a quadrilateral shape.

Embodiment 37 provides the abrasive article of Embodiment 36, wherein the polygonal shape is a quadrilateral shape.

Embodiment 38 provides the abrasive article of Embodiment 37, wherein the quadrilateral shape comprises a trapezoid, a square, or a rectangle.

Embodiment 39 provides the abrasive article of Embodiment 36, wherein the polygonal shape is a triangular shape.

Embodiment 40 provides the abrasive article of Embodiment 39, wherein the triangular shape comprises a right triangle, a scalene triangle, an isosceles triangle, an acute triangle, or an obtuse triangle.

Embodiment 41 provides the abrasive article of any one of Embodiments 39 or 40, wherein the triangular shape is free of an equilateral triangle.

Embodiment 42 provides the abrasive article of any one of Embodiments 39-41, wherein at least one of the shaped abrasive particles further comprises a third side surface having a triangular shape, wherein

the leading surface has a triangular shape, and

the shaped abrasive particle is a tetrahedron.

Embodiment 43 provides the abrasive article of any one of Embodiments 1-42 wherein a relief angle between the backing and a trailing surface or edge at a cutting tip of at least one of the shaped abrasive particles is in a range of from about 90 degrees to about 180 degrees.

Embodiment 44 provides the abrasive article of any one of Embodiments 1-43, wherein a relief angle between the backing and a trailing surface or edge at the cutting tip or at least one of the shaped abrasive particles is in a range of from about 120 degrees to about 140 degrees.

Embodiment 45 provides the abrasive article of any one of Embodiments 1-44, wherein the first side surface and the second side surface of at least one of the shaped abrasive particles are substantially the same size by at least one of surface area, a largest length dimension, and a largest width dimension.

Embodiment 46 provides the abrasive article of any one of Embodiments 1-45, wherein the first side surface and the second side surface of at least one of the shaped abrasive particles are different sizes by at least one of surface area, a largest length dimension, and a largest width dimension.

Embodiment 47 provides the abrasive article of any one of Embodiments 1-46, wherein the first side surface, the second side surface, and the leading surface of at least one of the shaped abrasive particles are substantially planar.

Embodiment 48 provides the abrasive article of any one of Embodiments 1-46, wherein at least one of the first side surface, the second side surface, and the leading surface of at least one of the shaped abrasive particles is substantially non-planar.

Embodiment 49 provides the abrasive article of any one of Embodiments 1-46, wherein the first side surface, the second side surface, and the leading surface of at least one of the shaped abrasive particles are substantially parallel to each other.

Embodiment 50 provides the abrasive article of any one of Embodiments 1-46, wherein the first side surface, the second side surface, and the leading surface of at least one of the shaped abrasive particles are substantially non-parallel to each other.

Embodiment 51 provides the abrasive article of any one of Embodiments 1-46, wherein at least one of the first side surface, the second side surface, and the leading surface of at least one of the shaped abrasive particles has a concave shape.

Embodiment 52 provides the abrasive article of Embodiment 46, wherein for at least one of the shaped abrasive particles:

the first side surface has a concave shape and the second side surface is substantially planar;

the first side surface has a convex shape and the second side surface has a concave shape; or

the first side surface is shaped inwardly and the second side surface is shaped inwardly.

Embodiment 53 provides the abrasive article of any one of Embodiments 1-28, wherein at least one of the shaped abrasive particles comprises at least one shape feature comprising: an opening, a concave surface, a convex surface, a groove, a ridge, a fractured surface, a low roundness factor, or a perimeter comprising one or more corner points having a sharp tip.

Embodiment 54 provides the abrasive article of any one of Embodiments 1-53, wherein at least one of the shaped abrasive particles comprises an opening.

Embodiment 55 provides the abrasive article of any one of Embodiments 1-54, wherein the first edge and the second edge of at least one of the shaped abrasive particles are substantially parallel.

Embodiment 56 provides the abrasive article of any one of Embodiments 1-55, wherein the first edge and the second edge of at least one of the shaped abrasive particles are tapered.

Embodiment 57 provides the abrasive article of any one of Embodiments 1-55, wherein the first edge and the second edge of at least one of the shaped abrasive particles are curved.

Embodiment 58 provides the abrasive article of any one of Embodiments 1-55, wherein a draft angle α between the second side surface and the leading surface of at least one of the shaped abrasive particles is in a range of from about 95 degrees and about 130 degrees.

Embodiment 59 provides the abrasive article of any one of Embodiments 1-58, wherein a cutting tip of at least one of the shaped abrasive particles is substantially aligned with the y-direction.

Embodiment 60 provides the abrasive article of any one of Embodiments 1-59, wherein the rake angle of at least one of the shaped abrasive particles is in a range of from about 80 degrees and about 100 degrees.

Embodiment 61 provides the abrasive article of any one of Embodiments 1-60, wherein the rake angle of at least one of the shaped abrasive particles is in a range of from about 85 degrees and about 95 degrees.

Embodiment 62 provides the abrasive article of any one of Embodiments 1-61, wherein the z-direction rotational angle of at least one of the shaped abrasive particles is in a range of from about 80 degrees and about 100 degrees.

Embodiment 63 provides the abrasive article of any one of Embodiments 1-62, wherein the z-direction rotational angle of at least one of the shaped abrasive particles is in a range of from about 85 degrees and about 95 degrees.

Embodiment 64 provides the abrasive article of any one of Embodiments 1-63, wherein for at least one of the shaped abrasive particles:

the first side surface and the second side surface comprise a triangular shape that is free of an equilateral triangular shape;

the first edge and the second edge are substantially parallel;

the rake angle is in a range of from about 80 degrees to about 110 degrees; and

the z-direction rotational angle is in a range of from about 80 degrees to about 110 degrees.

Embodiment 65 provides the abrasive article of Embodiment 64, wherein the triangular shape is a right triangle.

Embodiment 66 provides the abrasive article of any one of Embodiments 1-65, wherein an edge of at least one of the shaped abrasive particles is substantially aligned with the backing in an x-y plane.

Embodiment 67 provides the abrasive article of any one of Embodiments 1-66, wherein the at least one of the shaped abrasive particles is responsive to a magnetic field.

Embodiment 68 provides the abrasive article of any one of Embodiments 1-67, wherein at least one of the shaped abrasive particles comprises a magnetic material.

Embodiment 69 provides the abrasive article of Embodiment 68, wherein the magnetic material at least partially coats the surface of the shaped abrasive particle.

Embodiment 70 provides the abrasive article of Embodiment 69, wherein at least one of the shaped abrasive particles is monolithic abrasive particle.

Embodiment 71 provides the abrasive article of any one of Embodiments 1-70, wherein the rake angle of about 50% to about 100% of the shaped abrasive particles is substantially the same.

Embodiment 72 provides the abrasive article of any one of Embodiments 1-71, wherein the rake angle of about 90% to about 100% of the shaped abrasive particles is substantially the same.

Embodiment 73 provides the abrasive article of any one of Embodiments 1-72, wherein the z-direction rotational angle of about 50% to about 100% of the shaped abrasive particles is substantially the same.

Embodiment 74 provides the abrasive article of any one of Embodiments 1-73, wherein the z-direction rotational angle of about 90% to about 100% of the shaped abrasive particles is substantially the same.

Embodiment 75 provides the abrasive article of any one of Embodiments 1-74, further comprising crushed abrasive particles.

Embodiment 76 provides the abrasive article of Embodiment 75, wherein the crushed abrasive particles and the shaped abrasive particles comprise a different material.

Embodiment 77 provides the abrasive article of any one of Embodiments 75 or 76, wherein the shaped abrasive particles comprise about 5 wt % to about 95 wt % of a blend of the shaped abrasive particles and the crushed abrasive particles.

Embodiment 78 provides the abrasive article of any one of Embodiments 1-77, wherein the abrasive article comprises a belt, a disc, or a sheet.

Embodiment 79 provides the abrasive article of any one of Embodiments 1-78, further comprising a make coat adhering the shaped abrasive particles to the backing.

Embodiment 80 provides the abrasive article of Embodiment 79, further comprising a size coat adhering the shaped abrasive particles to the make coat.

Embodiment 81 provides the abrasive article of any one of Embodiments 79 or 80, wherein at least one of the make coat and the size coat comprise a phenolic resin, an epoxy resin, a urea-formaldehyde resin, an acrylate resin, an aminoplast resin, a melamine resin, an acrylated epoxy resin, a urethane resin, or mixtures thereof.

Embodiment 82 provides the abrasive article of any one of Embodiments 78-81, wherein at least one of the make coat and the size coat comprises a filler, a grinding aid, a wetting agent, a surfactant, a dye, a pigment, a coupling agent, an adhesion promoter, or a mixture thereof.

Embodiment 83 provides the abrasive article of Embodiment 82, wherein the filler comprises calcium carbonate, silica, talc, clay, calcium metasilicate, dolomite, aluminum sulfate, or a mixture thereof.

Embodiment 84 provides the abrasive article of any one of Embodiments 1-83, wherein the abrasive article comprises a disc and the z-direction rotational angle positions the leading surface circumferentially and a pattern created by the shaped abrasive particles comprises a plurality of circles.

Embodiment 85 provides the abrasive article of any one of Embodiments 1-84, wherein the abrasive article comprises a sheet or a belt and the z-direction rotational angle positions the substantially planar surface at an angle such that a pattern created by the shaped abrasive particles comprises a plurality of parallel lines.

Embodiment 86 provides a method of making the abrasive article of any one of Embodiments 1-85, the method comprising:

orienting the shaped abrasive particles; and

adhering the shaped abrasive particles to the backing.

Embodiment 87 provides the method of Embodiment 87, wherein orienting the shaped abrasive particles comprises depositing at least one of the shaped abrasive particles in a cavity of the backing that is shaped to result in at least one shaped abrasive particle having the z-direction rotational orientation.

Embodiment 88 provides the method of Embodiment 87, wherein orienting the shaped abrasive particles comprises passing the at least one of the shaped abrasive particles through a screen to result in the at least one shaped abrasive particle having the z-direction rotational orientation.

Embodiment 89 provides the method of Embodiment 88, wherein orienting the at least one shaped abrasive particle comprises placing the at least one shaped abrasive particle in an individual cavity of a transfer tool and contacting the at least one shaped abrasive particle with the backing to result in the at least one shaped abrasive particle having the z-direction rotational orientation.

Embodiment 90 provides the method of Embodiment 89, wherein orienting the at least one shaped abrasive particle comprises exposing the at least one shaped abrasive particle to a magnetic field.

Embodiment 91 provides the method of Embodiment 90, further comprising rotating the at least one shaped abrasive particle in the magnetic field.

Embodiment 92 provides the method of any one of Embodiments 87-91, wherein adhering the shaped abrasive particles to the backing comprises contacting the shaped abrasive particles with a make coat disposed over at least a portion of the backing.

Embodiment 93 provides the method of Embodiment 92, wherein adhering the shaped abrasive particles to the backing further comprises disposing a size coat over at least a portion of the shaped abrasive particles and at least one of the make coat and the backing.

Embodiment 94 provides a method of using the abrasive article according to any one of Embodiments 1-85 or made according to the method of any one of Embodiments 86-93, the method comprising:

contacting the shaped abrasive particles with a workpiece;

moving at least one of the abrasive article and the workpiece relative to each other in the direction of use; and

removing a portion of the workpiece.

Embodiment 95 provides the method of Embodiment 94, wherein a cutting tip of the at least one of the shaped abrasive particles contacts the workpiece.

Embodiment 96 provides the method of Embodiment 95, wherein the cutting tip is free of a sharp point having a radius of curvature of at least 60 microns.

Embodiment 97 provides the method of any one of Embodiments 94-96, wherein a cutting depth into the workpiece is at least 10 μm.

Embodiment 98 provides the method of any one of Embodiments 94-97, wherein a cutting depth into the workpiece is at least 30 μm.

Embodiment 99 provides the method of any one of Embodiments 94-98, wherein a cutting speed of the abrasive article is at least 100 m/min.

Embodiment 100 provides the method of any one of Embodiments 94-99, wherein a cutting speed of the abrasive article is at least 300 m/min.

Embodiment 101 provides the method of any one of Embodiments 94-100, wherein at least a portion of the workpiece is removed by the abrasive article as a swarf.

Embodiment 102 provides the method of Embodiment 101, wherein a longest average dimension of the individual swarfs generated in one grinding cycle is at least 1200 μm millimeters.

Embodiment 103 provides the method of any one of Embodiments 101 or 102, wherein a longest average dimension of the individual swarfs generated in one grinding cycle is at least 1772 nm.

Embodiment 104 provides the method of any one of Embodiments 102 or 103, wherein the swarf comprises low carbon steel.

Embodiment 105 provides the method of any one of Embodiments 94-104, wherein the direction of use is a first direction and under the same testing conditions the amount of material removed from the workpiece is greater in the first direction than in a second direction different than the first direction.

Embodiment 106 provides the method of any one of Embodiments 94-105, wherein the direction of use is a first direction and under the same testing conditions the amount of force required to remove the same amount of material from the workpiece is less than the amount of force required to remove the same amount of material at the same infeed rate when the direction of use is a second direction different than the first direction.

Embodiment 107 provides the method of Embodiment 106, wherein a workpiece infeed rate is about 110 mm/s to about 200 mm/s.

Embodiment 108 provides the method of any one of Embodiments 106 or 107, wherein a workpiece infeed rate is about 140 mm/s to about 160 mm/s.

Embodiment 109 provides the method of Embodiment 105, wherein the article is moved in the second direction to finish the workpiece.

Embodiment 110 provides the method of any one of Embodiments 98-109, wherein the direction of use is a linear direction or a rotational direction.

Embodiment 111 provides the method of Embodiment 110, wherein the direction of use is a rotational direction and the z-direction rotational angle is between the line intersecting the first edge and second edge and a line tangent to the rotational direction.

Embodiment 112 provides the method of Embodiment 111, wherein the abrasive article is a belt or a sheet and the direction of use is along an x-axis that is orthogonal to the y-axis and the z-axis.

Embodiment 113 provides the method of any one of Embodiments 94-112, wherein the workpiece comprises steel, aluminum, alloys thereof, wood, or mixtures thereof.

Embodiment 114 provides the method of any one of Embodiments 94-113, wherein an amount of workpiece material removed at an applied force to the abrasive article is greater than a corresponding abrasive article comprising shaped abrasive particles comprising equilateral triangles.

Embodiment 115 provides the method of any one of Embodiments 94-114, wherein an arithmetical mean roughness value of the workpiece material is in a range of from about 1000 to about 2000 when the abrasive article is moved in the first direction of use.

Embodiment 116 provides the method of any one of Embodiments 94-115, wherein an arithmetical mean roughness value of the workpiece material is in a range of from about 1000 to about 1100 when the abrasive article is moved in the first direction of use.

Embodiment 117 provides the method of any one of Embodiments 94-116, wherein an arithmetical mean roughness value of the workpiece material is higher when the abrasive article is moved in the first direction of use then when the abrasive article is moved in the second direction of use.

The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the embodiments of the present disclosure. Thus, it should be understood that although the present disclosure has been specifically disclosed by specific embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those of ordinary skill in the art, and that such modifications and variations are considered to be within the scope of embodiments of the present disclosure. 

1. An abrasive article having a first direction of use, the abrasive article comprising: abrasive particles attached to a backing, and wherein under the same testing conditions an amount of material removed from a workpiece in contact with the abrasive article is greater than an amount of material of the workpiece that is removed when the abrasive article is moved in a second direction different than the first direction of use.
 2. The abrasive article of claim 2, wherein at least 15% more material is removed in the first direction of use.
 3. The abrasive article of claim 1, wherein at least 50% more material is removed in the first direction of use.
 4. The abrasive article of claim 1, wherein the material is removed according to at least one of Grinding Procedure A and Grinding Procedure B.
 5. An abrasive article having a direction of use, a y-axis, and a z-axis orthogonal to the y-axis and the direction of use, the abrasive article comprising: a backing; shaped abrasive particles attached to the backing, about 5% to about 100% of the shaped abrasive particles independently comprising: a first side surface, a second side surface opposed to the first side surface, a leading surface connected to the first side surface at a first edge and connected to the second side surface at a second edge, a rake angle between the backing and the leading surface in a range of from about 10 degrees to about 110 degrees, and a z-direction rotational angle between a line intersecting the first edge and second edge and the direction of use of the abrasive article in a range of from about 10 degrees to about 170 degrees.
 6. The abrasive article of claim 5, wherein at least one of the shaped abrasive particles is a ceramic shaped abrasive particle.
 7. The abrasive article of claim 5, wherein the rake angle of at least one of the shaped abrasive particles is in a range between about 80 degrees and about 100 degrees.
 8. The abrasive article of claim 5, wherein the rake angle of at least one of the shaped abrasive particles is in a range between about 85 degrees and about 95 degrees.
 9. The abrasive article of claim 5, wherein the z-direction rotational angle of at least one of the shaped abrasive particles is in a range between about 80 degrees and about 100 degrees.
 10. The abrasive article of claim 5, wherein the z-direction rotational angle of at least one of the shaped abrasive particles is in a range between about 85 degrees and about 95 degrees.
 11. The abrasive article of claim 5, wherein a relief angle between the backing and a trailing surface or edge at a cutting tip of at least one of the shaped abrasive particles is in a range of from about 90 degrees to about 180 degrees.
 12. The abrasive article of claim 5, wherein an edge of at least one of the shaped abrasive particles is substantially aligned with the backing in an x-y plane.
 13. The abrasive article of claim 5, wherein the rake angle of about 50% to about 100% of the shaped abrasive particles is substantially the same.
 14. The abrasive article of claim 5, wherein the z-direction rotational angle of about 90% to about 100% of the shaped abrasive particles is substantially the same.
 15. The abrasive article of claim 5, further comprising crushed abrasive particles.
 16. A method of using the abrasive article according to claim 5, the method comprising: contacting the shaped abrasive particles with a workpiece; moving at least one of the abrasive article and the workpiece relative to each other in the direction of use; and removing a portion of material of the workpiece.
 17. The method of claim 16, wherein the direction of use is a first direction under the same testing conditions the portion of material removed from the workpiece is greater in the first direction than in a second direction different than the first direction.
 18. The method of claim 16, wherein the article is moved in the second direction to finish the workpiece.
 19. The method of claim 16, wherein the direction of use is a linear direction or a rotational direction.
 20. The method of claim 16, wherein the workpiece comprises steel, aluminum, alloys thereof, wood, or mixtures thereof. 